Programs & Examples On #Uiview

UIView is a class in the UIKit framework of iOS defines a rectangular area on the screen and the interfaces for managing the content in that area. All UI elements are either subclasses of UIView or are contained within a UIView.

Is it possible to set UIView border properties from interface builder?

You can make a category of UIView and add this in .h file of category

@property (nonatomic) IBInspectable UIColor *borderColor;
@property (nonatomic) IBInspectable CGFloat borderWidth;
@property (nonatomic) IBInspectable CGFloat cornerRadius;

Now add this in .m file

@dynamic borderColor,borderWidth,cornerRadius;

and this as well in . m file

-(void)setBorderColor:(UIColor *)borderColor{
    [self.layer setBorderColor:borderColor.CGColor];

    [self.layer setBorderWidth:borderWidth];

    [self.layer setCornerRadius:cornerRadius];

now you will see this in your storyboard for all UIView subclasses (UILabel, UITextField, UIImageView etc)

enter image description here

Thats it.. No Need to import category anywhere, just add the category's files in the project and see these properties in the storyboard.

UIView's frame, bounds, center, origin, when to use what?

They are related values, and kept consistent by the property setter/getter methods (and using the fact that frame is a purely synthesized value, not backed by an actual instance variable).

The main equations are:

frame.origin = center - bounds.size / 2

(which is the same as)

center = frame.origin + bounds.size / 2

(and there’s also)

frame.size = bounds.size

That's not code, just equations to express the invariant between the three properties. These equations also assume your view's transform is the identity, which it is by default. If it's not, then bounds and center keep the same meaning, but frame can change. Unless you're doing non-right-angle rotations, the frame will always be the transformed view in terms of the superview's coordinates.

This stuff is all explained in more detail with a useful mini-library here:

How to add a border just on the top side of a UIView

Swift 4.2 and AutoLayout

I went through the offered solutions. Many are based in frames This is a simple extension that works with AutoLayout - use View instead of Layer to make sure we can use AutoLayout - Single subview with 4 constraints

Use as follows:

self.addBorder(.bottom, color: .lightGray, thickness: 0.5)

extension UIView {
    func addBorder(_ edge: UIRectEdge, color: UIColor, thickness: CGFloat) {
        let subview = UIView()
        subview.translatesAutoresizingMaskIntoConstraints = false
        subview.backgroundColor = color
        switch edge {
        case .top, .bottom:
            subview.leftAnchor.constraint(equalTo: self.leftAnchor, constant: 0).isActive = true
            subview.rightAnchor.constraint(equalTo: self.rightAnchor, constant: 0).isActive = true
            subview.heightAnchor.constraint(equalToConstant: thickness).isActive = true
            if edge == .top {
                subview.topAnchor.constraint(equalTo: self.topAnchor, constant: 0).isActive = true
            } else {
                subview.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: 0).isActive = true
        case .left, .right:
            subview.topAnchor.constraint(equalTo: self.topAnchor, constant: 0).isActive = true
            subview.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: 0).isActive = true
            subview.widthAnchor.constraint(equalToConstant: thickness).isActive = true
            if edge == .left {
                subview.leftAnchor.constraint(equalTo: self.leftAnchor, constant: 0).isActive = true
            } else {
                subview.rightAnchor.constraint(equalTo: self.rightAnchor, constant: 0).isActive = true

How can I mimic the bottom sheet from the Maps app?

Maybe you can try my answer, inspired by Pulley. Smooth transition from moving the drawer to scrolling the list. I added a pan gesture on the container scroll view, and set shouldRecognizeSimultaneouslyWithGestureRecognizer to return YES. More detail in my github link above. Wish to help.

IOS: verify if a point is inside a rect

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
            UITouch *touch = [[event allTouches] anyObject];
            CGPoint touchLocation = [touch locationInView:self.view];
            CGRect rect1 = CGRectMake(vwTable.frame.origin.x, 
            vwTable.frame.origin.y, vwTable.frame.size.width, 
            if (CGRectContainsPoint(rect1,touchLocation))

UIView touch event in controller

Create outlets from views that were created in StoryBoard.

@IBOutlet weak var redView: UIView!
@IBOutlet weak var orangeView: UIView!
@IBOutlet weak var greenView: UIView!   

Override the touchesBegan method. There are 2 options, everyone can determine which one is better for him.

  1. Detect touch in special view.

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
         if let touch = touches.first {
            if touch.view == self.redView {
            } else if touch.view == self.orangeView {
            } else if touch.view == self.greenView {
            } else {
  2. Detect touch point on special view.

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        if let touch = touches.first {
            let location = touch.location(in: view)
            if redView.frame.contains(location) {
            } else if orangeView.frame.contains(location) {
            } else if greenView.frame.contains(location) {

Lastly, you need to declare the functions that will be called, depending on which view the user clicked.

func redViewTapped() {

func orangeViewTapped() {

func greenViewTapped() {

Making view resize to its parent when added with addSubview

that's all you need

childView.frame = parentView.bounds

How to find topmost view controller on iOS

Here is what worked for me.

I found that sometimes the controller was nil on the key window, as the keyWindow is some OS thing like an alert, etc.

 + (UIViewController*)topMostController
     UIWindow *topWndow = [UIApplication sharedApplication].keyWindow;
     UIViewController *topController = topWndow.rootViewController;

     if (topController == nil)
         // The windows in the array are ordered from back to front by window level; thus,
         // the last window in the array is on top of all other app windows.
         for (UIWindow *aWndow in [[UIApplication sharedApplication].windows reverseObjectEnumerator])
             topController = aWndow.rootViewController;
             if (topController)

     while (topController.presentedViewController) {
         topController = topController.presentedViewController;

     return topController;

How to load a xib file in a UIView

Create a XIB file :

File -> new File ->ios->cocoa touch class -> next

enter image description here

make sure check mark "also create XIB file"

I would like to perform with tableview so I choosed subclass UITableViewCell

you can choose as your requerment

enter image description here

XIB file desing as your wish (RestaurantTableViewCell.xib)

enter image description here

we need to grab the row height to set table each row hegiht

enter image description here

Now! need to huck them swift file . i am hucked the restaurantPhoto and restaurantName you can huck all of you .

enter image description here

Now adding a UITableView

enter image description here

The name of the nib file, which need not include the .nib extension.

The object to assign as the nib’s File's Owner object.

A dictionary containing the options to use when opening the nib file.

first if you do not define first then grabing all view .. so you need to grab one view inside that set frist .

Bundle.main.loadNibNamed("yourUIView", owner: self, options: nil)?.first as! yourUIView

here is table view controller Full code

import UIKit

class RestaurantTableViewController: UIViewController ,UITableViewDataSource,UITableViewDelegate{

    override func viewDidLoad() {

        // Do any additional setup after loading the view.

    override func didReceiveMemoryWarning() {
        // Dispose of any resources that can be recreated.
    func numberOfSections(in tableView: UITableView) -> Int {
        return 1

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 5
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let restaurantTableviewCell = Bundle.main.loadNibNamed("RestaurantTableViewCell", owner: self, options: nil)?.first as! RestaurantTableViewCell

        restaurantTableviewCell.restaurantPhoto.image = UIImage(named: "image1")
        restaurantTableviewCell.restaurantName.text = "KFC Chicken"

        return restaurantTableviewCell
   // set row height
    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        return 150


you done :)

enter image description here

UIView with rounded corners and drop shadow?

I write this UIView category method to solve this problem, uses separate views for the shadow and the corner radius.

-(UIView *)shadowedWrapViewWithBounds:(CGRect)bounds {
UIView *baseView = [[UIView alloc] init];
baseView.bounds = bounds;
baseView.backgroundColor = [UIColor clearColor];
baseView.layer.shadowColor = [UIColor blackColor].CGColor;
baseView.layer.shadowOffset = CGSizeMake(0, 0);
baseView.layer.shadowOpacity = 0.7;
baseView.layer.shadowRadius = 4.0;

// improve performance
baseView.layer.shadowPath = [UIBezierPath bezierPathWithRoundedRect:baseView.bounds cornerRadius:4].CGPath;
baseView.layer.shouldRasterize = YES;
baseView.layer.rasterizationScale = [UIScreen mainScreen].scale;

[baseView addSubview:self];
//use Masonry autolayout, self can set corner radius
[self makeConstraints:^(MASConstraintMaker *make) {

return baseView;

What's the best way to add a drop shadow to my UIView

On viewWillLayoutSubviews:

override func viewWillLayoutSubviews() {
    sampleView.layer.masksToBounds =  false
    sampleView.layer.shadowColor = UIColor.darkGrayColor().CGColor;
    sampleView.layer.shadowOffset = CGSizeMake(2.0, 2.0)
    sampleView.layer.shadowOpacity = 1.0

Using Extension of UIView:

extension UIView {

    func addDropShadowToView(targetView:UIView? ){
        targetView!.layer.masksToBounds =  false
        targetView!.layer.shadowColor = UIColor.darkGrayColor().CGColor;
        targetView!.layer.shadowOffset = CGSizeMake(2.0, 2.0)
        targetView!.layer.shadowOpacity = 1.0



UIView Infinite 360 degree rotation animation?

Swift 5 UIView Extension using Keyframe Animations

This approach allows us to directly use the UIView.AnimationOptions.repeat

public extension UIView {

    func animateRotation(duration: TimeInterval, repeat: Bool, completion: ((Bool) -> ())?) {

        var options = UIView.KeyframeAnimationOptions(rawValue: UIView.AnimationOptions.curveLinear.rawValue)

        if `repeat` {

        UIView.animateKeyframes(withDuration: duration, delay: 0, options: options, animations: {

            UIView.addKeyframe(withRelativeStartTime: 0, relativeDuration: 0.25, animations: {
                self.transform = CGAffineTransform(rotationAngle: CGFloat.pi/2)

            UIView.addKeyframe(withRelativeStartTime: 0.25, relativeDuration: 0.25, animations: {
                self.transform = CGAffineTransform(rotationAngle: CGFloat.pi)

            UIView.addKeyframe(withRelativeStartTime: 0.5, relativeDuration: 0.25, animations: {
                self.transform = CGAffineTransform(rotationAngle: 3*CGFloat.pi/2)

            UIView.addKeyframe(withRelativeStartTime: 0.75, relativeDuration: 0.25, animations: {
                self.transform = CGAffineTransform(rotationAngle: 2*CGFloat.pi)

        }, completion: completion)



How to add a touch event to a UIView?


UIControl *headerView = [[UIControl alloc] initWithFrame:CGRectMake(0, 0, tableView.bounds.size.width, nextY)];
[headerView addTarget:self action:@selector(myEvent:) forControlEvents:UIControlEventTouchDown];


let headerView = UIControl(frame: CGRect(x: 0, y: 0, width: tableView.bounds.size.width, height: nextY))
headerView.addTarget(self, action: #selector(myEvent(_:)), for: .touchDown)

The question asks:

How do I add a touch event to a UIView?

It isn't asking for a tap event.

Specifically OP wants to implement UIControlEventTouchDown

Switching the UIView to UIControl is the right answer here because Gesture Recognisers don't know anything about .touchDown, .touchUpInside, .touchUpOutside etc.

Additionally, UIControl inherits from UIView so you're not losing any functionality.

If all you want is a tap, then you can use the Gesture Recogniser. But if you want finer control, like this question asks for, you'll need UIControl.

How to add a footer to the UITableView?

You need to implement the UITableViewDelegate method

- (UIView *)tableView:(UITableView *)tableView viewForFooterInSection:(NSInteger)section

and return the desired view (e.g. a UILabel with the text you'd like in the footer) for the appropriate section of the table.

Given a view, how do I get its viewController?

Yes, the superview is the view that contains your view. Your view shouldn't know which exactly is its view controller, because that would break MVC principles.

The controller, on the other hand, knows which view it's responsible for (self.view = myView), and usually, this view delegates methods/events for handling to the controller.

Typically, instead of a pointer to your view, you should have a pointer to your controller, which in turn can either execute some controlling logic, or pass something to its view.

How do I change UIView Size?

Swift 3 and Swift 4:

myView.frame = CGRect(x: 0, y: 0, width: 0, height: 0)

Remove all constraints affecting a UIView


Following UIView Extension will remove all Edge constraints of a view:

extension UIView {
    func removeAllConstraints() {
        if let _superview = self.superview {

How to set cornerRadius for only top-left and top-right corner of a UIView?

Here is a Swift version of @JohnnyRockex answer

extension UIView {

    func roundCorners(_ corners: UIRectCorner, radius: CGFloat) {
         let path = UIBezierPath(roundedRect: self.bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
         let mask = CAShapeLayer()
         mask.path = path.cgPath
         self.layer.mask = mask


view.roundCorners([.topLeft, .bottomRight], radius: 10)


If you're using Auto Layout, you'll need to subclass your UIView and call roundCorners in the view's layoutSubviews for optimal effect.

class View: UIView {
    override func layoutSubviews() {

        self.roundCorners([.topLeft, .bottomLeft], radius: 10)

How to tell if UIViewController's view is visible

Good point that view is appeared if it's already in window hierarchy stack. thus we can extend our classes for this functionality.

extension UIViewController {
  var isViewAppeared: Bool { viewIfLoaded?.isAppeared == true }

extension UIView {
  var isAppeared: Bool { window != nil }

Draw line in UIView

One other (and an even shorter) possibility. If you're inside drawRect, something like the following:

[[UIColor blackColor] setFill];

Load view from an external xib file in storyboard

My full example is here, but I will provide a summary below.


Add a .swift and .xib file each with the same name to your project. The .xib file contains your custom view layout (using auto layout constraints preferably).

Make the swift file the xib file's owner.

enter image description here Code

Add the following code to the .swift file and hook up the outlets and actions from the .xib file.

import UIKit
class ResuableCustomView: UIView {

    let nibName = "ReusableCustomView"
    var contentView: UIView?

    @IBOutlet weak var label: UILabel!
    @IBAction func buttonTap(_ sender: UIButton) {
        label.text = "Hi"

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)

        guard let view = loadViewFromNib() else { return }
        view.frame = self.bounds
        contentView = view

    func loadViewFromNib() -> UIView? {
        let bundle = Bundle(for: type(of: self))
        let nib = UINib(nibName: nibName, bundle: bundle)
        return nib.instantiate(withOwner: self, options: nil).first as? UIView

Use it

Use your custom view anywhere in your storyboard. Just add a UIView and set the class name to your custom class name.

enter image description here

For a while Christopher Swasey's approach was the best approach I had found. I asked a couple of the senior devs on my team about it and one of them had the perfect solution! It satisfies every one of the concerns that Christopher Swasey so eloquently addressed and it doesn't require boilerplate subclass code(my main concern with his approach). There is one gotcha, but other than that it is fairly intuitive and easy to implement.

  1. Create a custom UIView class in a .swift file to control your xib. i.e. MyCustomClass.swift
  2. Create a .xib file and style it as you want. i.e. MyCustomClass.xib
  3. Set the File's Owner of the .xib file to be your custom class (MyCustomClass)
  4. GOTCHA: leave the class value (under the identity Inspector) for your custom view in the .xib file blank. So your custom view will have no specified class, but it will have a specified File's Owner.
  5. Hook up your outlets as you normally would using the Assistant Editor.
    • NOTE: If you look at the Connections Inspector you will notice that your Referencing Outlets do not reference your custom class (i.e. MyCustomClass), but rather reference File's Owner. Since File's Owner is specified to be your custom class, the outlets will hook up and work propery.
  6. Make sure your custom class has @IBDesignable before the class statement.
  7. Make your custom class conform to the NibLoadable protocol referenced below.
    • NOTE: If your custom class .swift file name is different from your .xib file name, then set the nibName property to be the name of your .xib file.
  8. Implement required init?(coder aDecoder: NSCoder) and override init(frame: CGRect) to call setupFromNib() like the example below.
  9. Add a UIView to your desired storyboard and set the class to be your custom class name (i.e. MyCustomClass).
  10. Watch IBDesignable in action as it draws your .xib in the storyboard with all of it's awe and wonder.

Here is the protocol you will want to reference:

public protocol NibLoadable {
    static var nibName: String { get }

public extension NibLoadable where Self: UIView {

    public static var nibName: String {
        return String(describing: Self.self) // defaults to the name of the class implementing this protocol.

    public static var nib: UINib {
        let bundle = Bundle(for: Self.self)
        return UINib(nibName: Self.nibName, bundle: bundle)

    func setupFromNib() {
        guard let view = Self.nib.instantiate(withOwner: self, options: nil).first as? UIView else { fatalError("Error loading \(self) from nib") }
        view.translatesAutoresizingMaskIntoConstraints = false
        view.leadingAnchor.constraint(equalTo: self.safeAreaLayoutGuide.leadingAnchor, constant: 0).isActive = true
        view.topAnchor.constraint(equalTo: self.safeAreaLayoutGuide.topAnchor, constant: 0).isActive = true
        view.trailingAnchor.constraint(equalTo: self.safeAreaLayoutGuide.trailingAnchor, constant: 0).isActive = true
        view.bottomAnchor.constraint(equalTo: self.safeAreaLayoutGuide.bottomAnchor, constant: 0).isActive = true

And here is an example of MyCustomClass that implements the protocol (with the .xib file being named MyCustomClass.xib):

class MyCustomClass: UIView, NibLoadable {

    @IBOutlet weak var myLabel: UILabel!

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)

    override init(frame: CGRect) {
        super.init(frame: frame)


NOTE: If you miss the Gotcha and set the class value inside your .xib file to be your custom class, then it will not draw in the storyboard and you will get a EXC_BAD_ACCESS error when you run the app because it gets stuck in an infinite loop of trying to initialize the class from the nib using the init?(coder aDecoder: NSCoder) method which then calls Self.nib.instantiate and calls the init again.

What is the most robust way to force a UIView to redraw?

The guaranteed, rock solid way to force a UIView to re-render is [myView setNeedsDisplay]. If you're having trouble with that, you're likely running into one of these issues:

  • You're calling it before you actually have the data, or your -drawRect: is over-caching something.

  • You're expecting the view to draw at the moment you call this method. There is intentionally no way to demand "draw right now this very second" using the Cocoa drawing system. That would disrupt the entire view compositing system, trash performance and likely create all kinds of artifacting. There are only ways to say "this needs to be drawn in the next draw cycle."

If what you need is "some logic, draw, some more logic," then you need to put the "some more logic" in a separate method and invoke it using -performSelector:withObject:afterDelay: with a delay of 0. That will put "some more logic" after the next draw cycle. See this question for an example of that kind of code, and a case where it might be needed (though it's usually best to look for other solutions if possible since it complicates the code).

If you don't think things are getting drawn, put a breakpoint in -drawRect: and see when you're getting called. If you're calling -setNeedsDisplay, but -drawRect: isn't getting called in the next event loop, then dig into your view hierarchy and make sure you're not trying to outsmart is somewhere. Over-cleverness is the #1 cause of bad drawing in my experience. When you think you know best how to trick the system into doing what you want, you usually get it doing exactly what you don't want.

How to add an UIViewController's view as subview

Thanks to this guys I did it

Add UIView, connect it to header:

@property (weak, nonatomic) IBOutlet UIView *addViewToAddPlot;

In - (void)viewDidLoad do this:

ViewControllerToAdd *nonSystemsController = [[ViewControllerToAdd alloc] initWithNibName:@"ViewControllerToAdd" bundle:nil];
    nonSystemsController.view.frame = self.addViewToAddPlot.bounds;
    [self.addViewToAddPlot addSubview:nonSystemsController.view];
    [self addChildViewController:nonSystemsController];
    [nonSystemsController didMoveToParentViewController:self];


UIView frame, bounds and center

This question already has a good answer, but I want to supplement it with some more pictures. My full answer is here.

To help me remember frame, I think of a picture frame on a wall. Just like a picture can be moved anywhere on the wall, the coordinate system of a view's frame is the superview. (wall=superview, frame=view)

To help me remember bounds, I think of the bounds of a basketball court. The basketball is somewhere within the court just like the coordinate system of the view's bounds is within the view itself. (court=view, basketball/players=content inside the view)

Like the frame, is also in the coordinates of the superview.

Frame vs Bounds - Example 1

The yellow rectangle represents the view's frame. The green rectangle represents the view's bounds. The red dot in both images represents the origin of the frame or bounds within their coordinate systems.

    origin = (0, 0)
    width = 80
    height = 130

    origin = (0, 0)
    width = 80
    height = 130

enter image description here

Example 2

    origin = (40, 60)  // That is, x=40 and y=60
    width = 80
    height = 130

    origin = (0, 0)
    width = 80
    height = 130

enter image description here

Example 3

    origin = (20, 52)  // These are just rough estimates.
    width = 118
    height = 187

    origin = (0, 0)
    width = 80
    height = 130

enter image description here

Example 4

This is the same as example 2, except this time the whole content of the view is shown as it would look like if it weren't clipped to the bounds of the view.

    origin = (40, 60)
    width = 80
    height = 130

    origin = (0, 0)
    width = 80
    height = 130

enter image description here

Example 5

    origin = (40, 60)
    width = 80
    height = 130

    origin = (280, 70)
    width = 80
    height = 130

enter image description here

Again, see here for my answer with more details.

Swift addsubview and remove it

You have to use the viewWithTag function to find the view with the given tag.

override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
    let touch = touches.anyObject() as UITouch
    let point = touch.locationInView(self.view)

    if let viewWithTag = self.view.viewWithTag(100) {
        print("Tag 100")
    } else {
        print("tag not found")

How to fill background image of an UIView


UIImage *img = [UIImage imageNamed:@"bg.png"];
view.backgroundColor = [UIColor colorWithPatternImage:img];


UIImage *img = [UIImage imageNamed:@"bg.png"];
view.layer.contents = img.CGImage;

iPhone UIView Animation Best Practice

Anyway the "Block" method is preffered now-a-days. I will explain the simple block below.

Consider the snipped below. bug2 and bug 3 are imageViews. The below animation describes an animation with 1 second duration after a delay of 1 second. The bug3 is moved from its center to bug2's center. Once the animation is completed it will be logged "Center Animation Done!".

NSLog(@"Center animation triggered!");
CGPoint bug2Center =;

[UIView animateWithDuration:1
                    options: UIViewAnimationCurveEaseOut
            = bug2Center;
                 completion:^(BOOL finished){
                     NSLog(@"Center Animation Done!");

Hope that's clean!!!

How do I apply a perspective transform to a UIView?

As Ben said, you'll need to work with the UIView's layer, using a CATransform3D to perform the layer's rotation. The trick to get perspective working, as described here, is to directly access one of the matrix cells of the CATransform3D (m34). Matrix math has never been my thing, so I can't explain exactly why this works, but it does. You'll need to set this value to a negative fraction for your initial transform, then apply your layer rotation transforms to that. You should also be able to do the following:


UIView *myView = [[self subviews] objectAtIndex:0];
CALayer *layer = myView.layer;
CATransform3D rotationAndPerspectiveTransform = CATransform3DIdentity;
rotationAndPerspectiveTransform.m34 = 1.0 / -500;
rotationAndPerspectiveTransform = CATransform3DRotate(rotationAndPerspectiveTransform, 45.0f * M_PI / 180.0f, 0.0f, 1.0f, 0.0f);
layer.transform = rotationAndPerspectiveTransform;

Swift 5.0

if let myView = self.subviews.first {
    let layer = myView.layer
    var rotationAndPerspectiveTransform = CATransform3DIdentity
    rotationAndPerspectiveTransform.m34 = 1.0 / -500
    rotationAndPerspectiveTransform = CATransform3DRotate(rotationAndPerspectiveTransform, 45.0 * .pi / 180.0, 0.0, 1.0, 0.0)
    layer.transform = rotationAndPerspectiveTransform

which rebuilds the layer transform from scratch for each rotation.

A full example of this (with code) can be found here, where I've implemented touch-based rotation and scaling on a couple of CALayers, based on an example by Bill Dudney. The newest version of the program, at the very bottom of the page, implements this kind of perspective operation. The code should be reasonably simple to read.

The sublayerTransform you refer to in your response is a transform that is applied to the sublayers of your UIView's CALayer. If you don't have any sublayers, don't worry about it. I use the sublayerTransform in my example simply because there are two CALayers contained within the one layer that I'm rotating.

Add a border outside of a UIView (instead of inside)

Ok, there already is an accepted answer but I think there is a better way to do it, you just have to had a new layer a bit larger than your view and do not mask it to the bounds of the view's layer (which actually is the default behaviour). Here is the sample code :

CALayer * externalBorder = [CALayer layer];
externalBorder.frame = CGRectMake(-1, -1, myView.frame.size.width+2, myView.frame.size.height+2);
externalBorder.borderColor = [UIColor blackColor].CGColor;
externalBorder.borderWidth = 1.0;

[myView.layer addSublayer:externalBorder];
myView.layer.masksToBounds = NO;

Of course this is if you want your border to be 1 unity large, if you want more you adapt the borderWidth and the frame of the layer accordingly. This is better than using a second view a bit larger as a CALayer is lighter than a UIView and you don't have do modify the frame of myView, which is good for instance if myView is aUIImageView

N.B : For me the result was not perfect on simulator (the layer was not exactly at the right position so the layer was thicker on one side sometimes) but was exactly what is asked for on real device.


Actually the problem I talk about in the N.B was just because I had reduced the screen of the simulator, on normal size there is absolutely no issue

Hope it helps

Programmatically create a UIView with color gradient

To give gradient color to UIView (swift 4.2)

func makeGradientLayer(`for` object : UIView, startPoint : CGPoint, endPoint : CGPoint, gradientColors : [Any]) -> CAGradientLayer {
        let gradient: CAGradientLayer = CAGradientLayer()
        gradient.colors = gradientColors
        gradient.locations = [0.0 , 1.0]
        gradient.startPoint = startPoint
        gradient.endPoint = endPoint
        gradient.frame = CGRect(x: 0, y: 0, w: object.frame.size.width, h: object.frame.size.height)
        return gradient

How to use

let start : CGPoint = CGPoint(x: 0.0, y: 1.0)
let end : CGPoint = CGPoint(x: 1.0, y: 1.0)

let gradient: CAGradientLayer = makeGradientLayer(for: cell, startPoint: start, endPoint: end, gradientColors: [
                    UIColor(red:0.92, green:0.07, blue:0.4, alpha:1).cgColor,
                    UIColor(red:0.93, green:0.11, blue:0.14, alpha:1).cgColor

self.vwTemp.layer.insertSublayer(gradient, at: 0)

How do I write a custom init for a UIView subclass in Swift?

The init(frame:) version is the default initializer. You must call it only after initializing your instance variables. If this view is being reconstituted from a Nib then your custom initializer will not be called, and instead the init?(coder:) version will be called. Since Swift now requires an implementation of the required init?(coder:), I have updated the example below and changed the let variable declarations to var and optional. In this case, you would initialize them in awakeFromNib() or at some later time.

class TestView : UIView {
    var s: String?
    var i: Int?
    init(s: String, i: Int) {
        self.s = s
        self.i = i
        super.init(frame: CGRect(x: 0, y: 0, width: 100, height: 100))

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)

How Do I Take a Screen Shot of a UIView?

CGImageRef UIGetScreenImage();

Apple now allows us to use it in a public application, even though it's a private API

Giving UIView rounded corners

set cornerRadious Property for round View

set masksToBounds Boolean Value for image will not still be drawn outside the corner radius boundary

view.layer.cornerRadius = 5;

view.layer.masksToBounds = YES;

Load a UIView from nib in Swift

Swift 4 - 5.1 Protocol Extensions

public protocol NibInstantiatable {
    static func nibName() -> String

extension NibInstantiatable {
    static func nibName() -> String {
        return String(describing: self)

extension NibInstantiatable where Self: UIView {
    static func fromNib() -> Self {
        let bundle = Bundle(for: self)
        let nib = bundle.loadNibNamed(nibName(), owner: self, options: nil)
        return nib!.first as! Self


class MyView: UIView, NibInstantiatable {


This implementation assumes that the Nib has the same name as the UIView class. Ex. MyView.xib. You can modify this behavior by implementing nibName() in MyView to return a different name than the default protocol extension implementation.

In the xib the files owner is MyView and the root view class is MyView.


let view = MyView.fromNib()

UIView bottom border?

Swift 5.1. Use with two extension, method return CALayer, so you would reuse it to update frames.

enum Border: Int {
    case top = 0
    case bottom
    case right
    case left

extension UIView {
    func addBorder(for side: Border, withColor color: UIColor, borderWidth: CGFloat) -> CALayer {
       let borderLayer = CALayer()
       borderLayer.backgroundColor = color.cgColor

       let xOrigin: CGFloat = (side == .right ? frame.width - borderWidth : 0)
       let yOrigin: CGFloat = (side == .bottom ? frame.height - borderWidth : 0)

       let width: CGFloat = (side == .right || side == .left) ? borderWidth : frame.width
       let height: CGFloat = (side == .top || side == .bottom) ? borderWidth : frame.height

       borderLayer.frame = CGRect(x: xOrigin, y: yOrigin, width: width, height: height)
       return borderLayer

extension CALayer {
    func updateBorderLayer(for side: Border, withViewFrame viewFrame: CGRect) {
        let xOrigin: CGFloat = (side == .right ? viewFrame.width - frame.width : 0)
        let yOrigin: CGFloat = (side == .bottom ? viewFrame.height - frame.height : 0)

        let width: CGFloat = (side == .right || side == .left) ? frame.width : viewFrame.width
        let height: CGFloat = (side == .top || side == .bottom) ? frame.height : viewFrame.height

        frame = CGRect(x: xOrigin, y: yOrigin, width: width, height: height)

Bringing a subview to be in front of all other views

In c#, View.BringSubviewToFront(childView); YourView.Layer.ZPosition = 1; both should work.

How to add constraints programmatically using Swift

The problem, as the error message suggests, is that you have constraints of type NSAutoresizingMaskLayoutConstraints that conflict with your explicit constraints, because new_view.translatesAutoresizingMaskIntoConstraints is set to true.

This is the default setting for views you create in code. You can turn it off like this:

var new_view:UIView! = UIView(frame: CGRectMake(0, 0, 100, 100))
new_view.translatesAutoresizingMaskIntoConstraints = false

Also, your width and height constraints are weird. If you want the view to have a constant width, this is the proper way:

    item:new_view, attribute:NSLayoutAttribute.Width,
    toItem:nil, attribute:NSLayoutAttribute.NotAnAttribute,
    multiplier:0, constant:100))

(Replace 100 by the width you want it to have.)

If your deployment target is iOS 9.0 or later, you can use this shorter code:

new_view.widthAnchor.constraintEqualToConstant(100).active = true

Anyway, for a layout like this (fixed size and centered in parent view), it would be simpler to use the autoresizing mask and let the system translate the mask into constraints:

var new_view:UIView! = UIView(frame: CGRectMake(0, 0, 100, 100))
new_view.backgroundColor = UIColor.redColor();

// This is the default setting but be explicit anyway...
new_view.translatesAutoresizingMaskIntoConstraints = true

new_view.autoresizingMask = [ .FlexibleTopMargin, .FlexibleBottomMargin,
    .FlexibleLeftMargin, .FlexibleRightMargin ] = CGPointMake(view.bounds.midX, view.bounds.midY)

Note that using autoresizing is perfectly legitimate even when you're also using autolayout. (UIKit still uses autoresizing in lots of places internally.) The problem is that it's difficult to apply additional constraints to a view that is using autoresizing.

Simple way to change the position of UIView?

If anybody needs light Swift extension to change UIView margins easily - you can use this = 16
view.right = self.width
view.bottom = self.height
self.height = view.bottom

Get to UIViewController from UIView?

To Phil's answer:

In line: id nextResponder = [self nextResponder]; if self(UIView) is not a subview of ViewController's view, if you know hierarchy of self(UIView) you can use also: id nextResponder = [[self superview] nextResponder];...

How to set iPhone UIView z index?

You can use the zPosition property of the view's layer (it's a CALayer object) to change the z-index of the view.

theView.layer.zPosition = 1;

As Viktor Nordling added, "big values are on top. You can use any values you want, including negative values." The default value is 0.

You need to import the QuartzCore framework to access the layer. Just add this line of code at the top of your implementation file.

#import "QuartzCore/QuartzCore.h"

How to set background image of a view?

You can set multiple background image in every view using custom method as below.

make plist for every theam with background image name and other color

#import <Foundation/Foundation.h>
@interface ThemeManager : NSObject
@property (nonatomic,strong) NSDictionary*styles;
+ (ThemeManager *)sharedManager;

             #import "ThemeManager.h"

            @implementation ThemeManager
            @synthesize styles;
            + (ThemeManager *)sharedManager
                static ThemeManager *sharedManager = nil;
                if (sharedManager == nil)
                    sharedManager = [[ThemeManager alloc] init];
                [sharedManager selectTheme];
                return sharedManager;
            - (id)init
                if ((self = [super init]))

                return self;
                NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
                NSString *themeName = [defaults objectForKey:@"AppTheme"] ?: @"DefaultTheam";

                NSString *path = [[NSBundle mainBundle] pathForResource:themeName ofType:@"plist"];
                self.styles = [NSDictionary dictionaryWithContentsOfFile:path];

Can use this via

 NSDictionary *styles = [ThemeManager sharedManager].styles;
 NSString *imageName = [styles objectForKey:@"backgroundImage"];
[imgViewBackGround setImage:[UIImage imageNamed:imageName]];

How to use UIVisualEffectView to Blur Image?

You can also use the interface builder to create these effects easily for simple situations. Since the z-values of the views will depend on the order they are listed in the Document Outline, you can drag a UIVisualEffectView onto the document outline before the view you want to blur. This automatically creates a nested UIView, which is the contentView property of the given UIVisualEffectView. Nest things within this view that you want to appear on top of the blur.

XCode6 beta5

You can also easily take advantage of the vibrancy UIVisualEffect, which will automatically create another nested UIVisualEffectView in the document outline with vibrancy enabled by default. You can then add a label or text view to the nested UIView (again, the contentView property of the UIVisualEffectView), to achieve the same effect that the "> slide to unlock" UI element.

enter image description here

Cocoa: What's the difference between the frame and the bounds?

The bounds of an UIView is the rectangle, expressed as a location (x,y) and size (width,height) relative to its own coordinate system (0,0).

The frame of an UIView is the rectangle, expressed as a location (x,y) and size (width,height) relative to the superview it is contained within.

So, imagine a view that has a size of 100x100 (width x height) positioned at 25,25 (x,y) of its superview. The following code prints out this view's bounds and frame:

// This method is in the view controller of the superview
- (void)viewDidLoad {
    [super viewDidLoad];

    NSLog(@"bounds.origin.x: %f", label.bounds.origin.x);
    NSLog(@"bounds.origin.y: %f", label.bounds.origin.y);
    NSLog(@"bounds.size.width: %f", label.bounds.size.width);
    NSLog(@"bounds.size.height: %f", label.bounds.size.height);

    NSLog(@"frame.origin.x: %f", label.frame.origin.x);
    NSLog(@"frame.origin.y: %f", label.frame.origin.y);
    NSLog(@"frame.size.width: %f", label.frame.size.width);
    NSLog(@"frame.size.height: %f", label.frame.size.height);

And the output of this code is:

bounds.origin.x: 0
bounds.origin.y: 0
bounds.size.width: 100
bounds.size.height: 100

frame.origin.x: 25
frame.origin.y: 25
frame.size.width: 100
frame.size.height: 100

So, we can see that in both cases, the width and the height of the view is the same regardless of whether we are looking at the bounds or frame. What is different is the x,y positioning of the view. In the case of the bounds, the x and y coordinates are at 0,0 as these coordinates are relative to the view itself. However, the frame x and y coordinates are relative to the position of the view within the parent view (which earlier we said was at 25,25).

There is also a great presentation that covers UIViews. See slides 1-20 which not only explain the difference between frames and bounds but also show visual examples.

How to draw a custom UIView that is just a circle - iPhone app

Swift 3 - Xcode 8.1

@IBOutlet weak var myView: UIView!

override func viewDidLoad() {

    let size:CGFloat = 35.0
    myView.bounds = CGRect(x: 0, y: 0, width: size, height: size)
    myView.layer.cornerRadius = size / 2
    myView.layer.borderWidth = 1
    myView.layer.borderColor = UIColor.Gray.cgColor        

Move UIView up when the keyboard appears in iOS

Simple solution without adding observer notification

    [UIView beginAnimations:nil context:NULL];

    [UIView setAnimationDuration:0.3]; // if you want to slide up the view

    CGRect rect = self.view.frame;

    if (movedUp)
        // 1. move the view's origin up so that the text field that will be hidden come above the keyboard
        // 2. increase the size of the view so that the area behind the keyboard is covered up.
        rect.origin.y -= kOFFSET_FOR_KEYBOARD;
        rect.size.height += kOFFSET_FOR_KEYBOARD;
        // revert back to the normal state.
        rect.origin.y += kOFFSET_FOR_KEYBOARD;
        rect.size.height -= kOFFSET_FOR_KEYBOARD;
    self.view.frame = rect;

    [UIView commitAnimations];

-(void)textFieldDidEndEditing:(UITextField *)sender
     if  (self.view.frame.origin.y >= 0)
            [self setViewMovedUp:NO];

-(void)textFieldDidBeginEditing:(UITextField *)sender
        //move the main view, so that the keyboard does not hide it.
        if  (self.view.frame.origin.y >= 0)
            [self setViewMovedUp:YES];



iPhone - Get Position of UIView within entire UIWindow

For me this code worked best:

private func getCoordinate(_ view: UIView) -> CGPoint {
    var x = view.frame.origin.x
    var y = view.frame.origin.y
    var oldView = view

    while let superView = oldView.superview {
        x += superView.frame.origin.x
        y += superView.frame.origin.y
        if is UIViewController {
            break //superView is the rootView of a UIViewController
        oldView = superView

    return CGPoint(x: x, y: y)

Getting reference to the top-most view/window in iOS application

Whenever I want to display some overlay on top of everything else, I just add it on top of the Application Window directly:

[[[UIApplication sharedApplication] keyWindow] addSubview:someView]

Swift UIView background color opacity

The problem you have found is that view is different from your UIView. 'view' refers to the entire view. For example your home screen is a view.

You need to clearly separate the entire 'view' your 'UIView' and your 'UILabel'

You can accomplish this by going to your storyboard, clicking on the item, Identity Inspector, and changing the Restoration ID.

Now to access each item in your code using the restoration ID

Correct way to load a Nib for a UIView subclass

Follow the following steps

  1. Create a class named MyView .h/.m of type UIView.
  2. Create a xib of same name MyView.xib.
  3. Now change the File Owner class to UIViewController from NSObject in xib. See the image below enter image description here
  4. Connect the File Owner View to your View. See the image below enter image description here

  5. Change the class of your View to MyView. Same as 3.

  6. Place controls create IBOutlets.

Here is the code to load the View:

UIViewController *controller=[[UIViewController alloc] initWithNibName:@"MyView" bundle:nil];
MyView* view=(MyView*)controller.view;
[self.view addSubview:myview];

Hope it helps.


UIViewController is used to load your xib and the View which the UIViewController has is actually MyView which you have assigned in the MyView xib..

Demo I have made a demo grab here

SQL Server SELECT INTO @variable?

Sounds like you want temp tables.

Note that #TempTable is available throughout your SP.

Note the ##TempTable is available to all.

Common sources of unterminated string literal

I would vote for jamtoday's answer if I had the "reputation"

If your data is coming by way of PHP, this might help

$str = str_replace(array("\r", "\n"), '', $str);

How to check if a list is empty in Python?

Empty lists evaluate to False in boolean contexts (such as if some_list:).

remote rejected master -> master (pre-receive hook declined)

simple answer

$ heroku config:set DISABLE_COLLECTSTATIC=1


$ git push heroku master

Unable to resolve dependency for ':app@debug/compileClasspath': Could not resolve

For other people where the accepted answer does not solve this issue...

As of September 2018, AndroidX has replaced the Android Support Libraries, which includes the appcompat-v7 library.

'' becomes 'androidx.appcompat:appcompat:1.0.0'

'' becomes ''

References: List of Support Libraries to AndroidX mappings

how to check if string value is in the Enum list?

To parse the age:

Age age;
if (Enum.TryParse(typeof(Age), "New_Born", out age))
  MessageBox.Show("Defined");  // Defined for "New_Born, 1, 4 , 8, 12"

To see if it is defined:

if (Enum.IsDefined(typeof(Age), "New_Born"))

Depending on how you plan to use the Age enum, flags may not be the right thing. As you probably know, [Flags] indicates you want to allow multiple values (as in a bit mask). IsDefined will return false for Age.Toddler | Age.Preschool because it has multiple values.

What is the default font of Sublime Text?

On Linux it's Monospace 10 pt. (the exact monospace font used may vary on different Linux distributions or versions), on Windows it's Consolas 10 pt., and on OS X it's Menlo Regular 12 pt.

default platform preferences

(The color scheme is Neon, the syntax highlighting is from PackageDev, and the font is Liberation Mono

This information is found in the Packages/Default directory (where Packages is the directory opened by the Preferences ? Browse Packages... menu option), in the Preferences (OS).sublime-settings file where OS is one of Windows, Linux, or OSX.

You should only customize the font (or any other setting) in Packages/User/Preferences.sublime-settings, opened by Preferences ? Settings—User, as Settings—Default is over-written on upgrade, and also serves as a backup in case you really screw something up in your user settings. This is the case for both the main Sublime settings as well as those for extra packages/plugins.

These default fonts are the same in Sublime Text 2, Sublime Text 3, and the new version currently in development.

How do I create the small icon next to the website tab for my site?

It is called favicon.ico and you can generate it from this site.

How to access the request body when POSTing using Node.js and Express?

I'm absolutely new to JS and ES, but what seems to work for me is just this:


Let me know if there's anything wrong with it!

How to subtract 2 hours from user's local time?

Subtract from another date object

var d = new Date();

d.setHours(d.getHours() - 2);

CSS "color" vs. "font-color"

I would think that one reason could be that the color is applied to things other than font. For example:

div {
    border: 1px solid;
    color: red;

Yields both a red font color and a red border.

Alternatively, it could just be that the W3C's CSS standards are completely backwards and nonsensical as evidenced elsewhere.

How to replace NaN values by Zeroes in a column of a Pandas Dataframe?

You can also use dictionaries to fill NaN values of the specific columns in the DataFrame rather to fill all the DF with some oneValue.

import pandas as pd

df = pd.read_excel('example.xlsx')
df.fillna( {
        'column1': 'Write your values here',
        'column2': 'Write your values here',
        'column3': 'Write your values here',
        'column4': 'Write your values here',
        'column-n': 'Write your values here'} , inplace=True)

Move SQL data from one table to another

You should be able to with a subquery in the INSERT statement.

INSERT INTO table1(column1, column2) SELECT column1, column2 FROM table2 WHERE ...;

followed by deleting from table1.

Remember to run it as a single transaction so that if anything goes wrong you can roll the entire operation back.

Maximum filename length in NTFS (Windows XP and Windows Vista)?

238! I checked it under Win7 32 bit with the following bat script:

set "fname="
for /l %%i in (1, 1, 27) do @call :setname
@echo %fname%
for /l %%i in (1, 1, 100) do @call :check
goto :EOF
set "fname=%fname%_123456789"
goto :EOF
set "fname=%fname:~0,-1%"
@echo xx>%fname%
if not exist %fname% goto :eof
dir /b
goto :EOF

Linux/Unix command to determine if process is running?

On most Linux distributions, you can use pidof(8).

It will print the process ids of all running instances of specified processes, or nothing if there are no instances running.

For instance, on my system (I have four instances of bashand one instance of remmina running):

$ pidof bash remmina
6148 6147 6144 5603 21598

On other Unices, pgrep or a combination of ps and grep will achieve the same thing, as others have rightfully pointed out.

How to negate specific word in regex?

Extracted from this comment by bkDJ:


The nice property of this solution is that it's possible to clearly negate (exclude) multiple words:


How to launch another aspx web page upon button click?

Use an html button and javascript? in javascript, window.location is used to change the url location of the current window, while will open a new one

<input type="button" onclick="'newPage.aspx', 'newPage');" />

Edit: Ah, just found this: If the ID of your form tag is form1, set this attribute in your asp button

OnClientClick=" ='_blank';"

C# - Create SQL Server table programmatically

Try this:

protected void Button1_Click(object sender, EventArgs e)
    SqlConnection cn = new SqlConnection("Data Source=(LocalDB)\\v11.0;AttachDbFilename=|DataDirectory|\\Database.mdf;Integrated Security=True");
        SqlCommand cmd = new SqlCommand("create table Employee (empno int,empname varchar(50),salary money);", cn);
        lblAlert.Text = "SucessFully Connected";
    catch (Exception eq)
        lblAlert.Text = eq.ToString();

Handler "ExtensionlessUrlHandler-Integrated-4.0" has a bad module "ManagedPipelineHandler" in its module list

For me, removing WebDAV from my server caused the application to return a 503 Service Unavailable Error message when using PUT or DELETE, so I re-installed it back again. I also tried completely removing .NET Framework 4.5 and reinstalling it and also tried re-registering as suggested but to no avail.

I was able to fix this by disabling WebDAV for the individual application pool, this stopped the 'bad module' error when using PUT or DELETE.

Disable WebDAV for Individual App Pool:

  1. Click the affected application pool
  2. Find WebDAV Authoring Tools in the list
  3. Click to open it
  4. Click Disable WebDAV in the top right.

Ta daaaa!

I still left the remove items in my web.config file.

      <remove name="WebDAVModule"/>
      <remove name="WebDAV" />

This link is where I found the instructions but it's not very clear.

No resource found - Theme.AppCompat.Light.DarkActionBar

If you are using Eclipse just copying android-support-v7-appcompat.jar to libs folder will not work if you are going to use resources.

Follow steps from here for "Adding libraries with resources".

How to split a string of space separated numbers into integers?

l = (int(x) for x in s.split())

If you are sure there are always two integers you could also do:

a,b = (int(x) for x in s.split())

or if you plan on modifying the array after

l = [int(x) for x in s.split()]

Getting net::ERR_UNKNOWN_URL_SCHEME while calling telephone number from HTML page in Android

I had this issue occurring with mailto: and tel: links inside an iframe (in Chrome, not a webview). Clicking the links would show the grey "page not found" page and inspecting the page showed it had a ERR_UNKNOWN_URL_SCHEME error.

Adding target="_blank", as suggested by this discussion of the issue fixed the problem for me.

How to change the height of a <br>?

br {   
    content: "";
    margin: 2em;
    display: block;
    margin-bottom: -20px; 

Works in Firefox, Chrome & Safari. Haven't tested in Explorer. (Windows-tablet is out of power.)

Line-breaks, font-size works differently in Firefox & Safari.

Return the most recent record from ElasticSearch index

If you are using python elasticsearch5 module or curl:

  1. make sure each document that gets inserted has
    • a timestamp field that is type datetime
    • and you are monotonically increasing the timestamp value for each document
  2. from python you do

    es = elasticsearch5.Elasticsearch('my_host:my_port')

If your documents are not inserted with any field that is of type datetime, then I don't believe you can get the N "most recent".

How to set multiple commands in one yaml file with Kubernetes?

If you want to avoid concatenating all commands into a single command with ; or && you can also get true multi-line scripts using a heredoc:

 - sh
 - "-c"
 - |
   /bin/bash <<'EOF'

   # Normal script content possible here
   echo "Hello world"
   ls -l
   exit 123


This is handy for running existing bash scripts, but has the downside of requiring both an inner and an outer shell instance for setting up the heredoc.

Is there a conditional ternary operator in VB.NET?

Just for the record, here is the difference between If and IIf:

IIf(condition, true-part, false-part):

  • This is the old VB6/VBA Function
  • The function always returns an Object type, so if you want to use the methods or properties of the chosen object, you have to re-cast it with DirectCast or CType or the Convert.* Functions to its original type
  • Because of this, if true-part and false-part are of different types there is no matter, the result is just an object anyway

If(condition, true-part, false-part):

  • This is the new VB.NET Function
  • The result type is the type of the chosen part, true-part or false-part
  • This doesn't work, if Strict Mode is switched on and the two parts are of different types. In Strict Mode they have to be of the same type, otherwise you will get an Exception
  • If you really need to have two parts of different types, switch off Strict Mode (or use IIf)
  • I didn't try so far if Strict Mode allows objects of different type but inherited from the same base or implementing the same Interface. The Microsoft documentation isn't quite helpful about this issue. Maybe somebody here knows it.

Ruby 2.0.0p0 IRB warning: "DL is deprecated, please use Fiddle"

The message "DL is deprecated, please use Fiddle" is not an error; it's only a warning.
You can ignore this in 3 simple steps.
Step 1. Goto C:\RailsInstaller\Ruby2.1.0\lib\ruby\2.1.0
Step 2. Then find dl.rb and open the file with any online editors like Aptana,sublime text etc
Step 3. Comment the line 8 with '#' ie # warn "DL is deprecated, please use Fiddle" .
That's it, Thank you.

What is a smart pointer and when should I use one?

A smart pointer is a pointer-like type with some additional functionality, e.g. automatic memory deallocation, reference counting etc.

A small intro is available on the page Smart Pointers - What, Why, Which?.

One of the simple smart-pointer types is std::auto_ptr (chapter 20.4.5 of C++ standard), which allows one to deallocate memory automatically when it out of scope and which is more robust than simple pointer usage when exceptions are thrown, although less flexible.

Another convenient type is boost::shared_ptr which implements reference counting and automatically deallocates memory when no references to the object remains. This helps avoiding memory leaks and is easy to use to implement RAII.

The subject is covered in depth in book "C++ Templates: The Complete Guide" by David Vandevoorde, Nicolai M. Josuttis, chapter Chapter 20. Smart Pointers. Some topics covered:

Start index for iterating Python list

If all you want is to print from Monday onwards, you can use list's index method to find the position where "Monday" is in the list, and iterate from there as explained in other posts. Using list.index saves you hard-coding the index for "Monday", which is a potential source of error:

days = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday']
for d in days[days.index('Monday'):] :
   print d

How to put text in the upper right, or lower right corner of a "box" using css

If the position of the element containing the Lorum Ipsum is set absolute, you can specify the position via CSS. The "here" and "and here" elements would need to be contained in a block level element. I'll use markup like this.

print("<div id="lipsum">");
print("<div id="here">");
print("  here");
print("<div id="andhere">");
print("and here");

Here's the CSS for above.

#lipsum {position:absolute;top:0;left:0;} /* example */
#here {position:absolute;top:0;right:0;}
#andhere {position:absolute;bottom:0;right:0;}

Again, the above only works (reliably) if #lipsum is positioned via absolute.

If not, you'll need to use the float property.

#here, #andhere {float:right;}

You'll also need to put your markup in the appropriate place. For better presentation, your two divs will probably need some padding and margins so that the text doesn't all run together.

CSS Box Shadow - Top and Bottom Only

As Kristian has pointed out, good control over z-values will often solve your problems.

If that does not work you can take a look at CSS Box Shadow Bottom Only on using overflow hidden to hide excess shadow.

I would also have in mind that the box-shadow property can accept a comma-separated list of shadows like this:

box-shadow: 0px 10px 5px #888, 0px -10px 5px #888;

This will give you some control over the "amount" of shadow in each direction.

Have a look at for more information about box-shadow.

Hope this was what you were looking for!

Add a auto increment primary key to existing table in oracle

If you have the column and the sequence, you first need to populate a new key for all the existing rows. Assuming you don't care which key is assigned to which row

UPDATE table_name
   SET new_pk_column = sequence_name.nextval;

Once that's done, you can create the primary key constraint (this assumes that either there is no existing primary key constraint or that you have already dropped the existing primary key constraint)

ALTER TABLE table_name
  ADD CONSTRAINT pk_table_name PRIMARY KEY( new_pk_column )

If you want to generate the key automatically, you'd need to add a trigger

CREATE TRIGGER trigger_name
  BEFORE INSERT ON table_name
  :new.new_pk_column := sequence_name.nextval;

If you are on an older version of Oracle, the syntax is a bit more cumbersome

CREATE TRIGGER trigger_name
  BEFORE INSERT ON table_name
  SELECT sequence_name.nextval
    INTO :new.new_pk_column
    FROM dual;

SSL handshake alert: unrecognized_name error since upgrade to Java 1.7.0

I had the same problem with an Ubuntu Linux server running subversion when accessed via Eclipse.

It has shown that the problem had to do with a warning when Apache (re)started:

[Mon Jun 30 22:27:10 2014] [warn] NameVirtualHost *:80 has no VirtualHosts

... waiting [Mon Jun 30 22:27:11 2014] [warn] NameVirtualHost *:80 has no VirtualHosts

This has been due to a new entry in ports.conf, where another NameVirtualHost directive was entered alongside the directive in sites-enabled/000-default.

After removing the directive in ports.conf, the problem had vanished (after restarting Apache, naturally)

Download a file from NodeJS Server using Express

There are several ways to do it This is the better way'/report-12345.pdf')

or in your case this might be

app.get('/download', function(req, res){
  const file = `${__dirname}/upload-folder/dramaticpenguin.MOV`;; // Set disposition and send it.

Know More

Dynamically Dimensioning A VBA Array?

You need to use a constant.

CONST NumberOfZombies = 20000
Dim Zombies(NumberOfZombies) As Zombies

or if you want to use a variable you have to do it this way:

Dim NumberOfZombies As Integer
NumberOfZombies = 20000

Dim Zombies() As Zombies

ReDim Zombies(NumberOfZombies)

Find the number of downloads for a particular app in apple appstore

I think developers can do this for their own apps via iTunes Connect but this doesn't help you if you are looking for stats on other peoples apps.

148Apps also have some aggregate AppStore metrics on their web site that could be useful to you but, again, doesn't really give a low-level breakdown of numbers.

You could also scrape some stats from the RSS feeds generated by the iTunes Store RSS Generator but, again, this just gets currently popular apps rather than actual download numbers.

What process is listening on a certain port on Solaris?

I think the first answer is the best I wrote my own shell script developing this idea :

if [ $# -ne 1 ]
    echo "Sintaxis:\n\t"
    echo " $0 {port to search in process }"
    for i in `ls /proc`

       pfiles $i | grep port | grep "port: $MYPORT" > /dev/null
       if [ $? -eq 0 ]
           echo " Port $MYPORT founded in $i proccess !!!\n\n"
           echo "Details\n\t"
           pfiles $i | grep port | grep "port: $MYPORT"
           echo "\n\t"
           echo "Process detail: \n\t"
           ps -ef | grep $i  | grep -v grep

How to Select Min and Max date values in Linq Query

This should work for you

//Retrieve Minimum Date
var MinDate = (from d in dataRows select d.Date).Min();

//Retrieve Maximum Date
var MaxDate = (from d in dataRows select d.Date).Max(); 

(From here)

Getting "file not found" in Bridging Header when importing Objective-C frameworks into Swift project

Well its little strange but I guess you have to add a resource to your "Copy Bundle Resources" phase of your test target to make it load all headers from your main app target. In my case, I added main.storyboard and it took care of the error.

enter image description here

How to count check-boxes using jQuery?

The following code worked for me.


Replace preg_replace() e modifier with preg_replace_callback

preg_replace shim with eval support

This is very inadvisable. But if you're not a programmer, or really prefer terrible code, you could use a substitute preg_replace function to keep your /e flag working temporarily.

 * Can be used as a stopgap shim for preg_replace() calls with /e flag.
 * Is likely to fail for more complex string munging expressions. And
 * very obviously won't help with local-scope variable expressions.
 * @license: CC-BY-*.*-comment-must-be-retained
 * @security: Provides `eval` support for replacement patterns. Which
 *   poses troubles for user-supplied input when paired with overly
 *   generic placeholders. This variant is only slightly stricter than
 *   the C implementation, but still susceptible to varexpression, quote
 *   breakouts and mundane exploits from unquoted capture placeholders.
 * @url:
function preg_replace_eval($pattern, $replacement, $subject, $limit=-1) {
    # strip /e flag
    $pattern = preg_replace('/(\W[a-df-z]*)e([a-df-z]*)$/i', '$1$2', $pattern);
    # warn about most blatant misuses at least
    if (preg_match('/\(\.[+*]/', $pattern)) {
        trigger_error("preg_replace_eval(): regex contains (.*) or (.+) placeholders, which easily causes security issues for unconstrained/user input in the replacement expression. Transform your code to use preg_replace_callback() with a sane replacement callback!");
    # run preg_replace with eval-callback
    return preg_replace_callback(
        function ($matches) use ($replacement) {
            # substitute $1/$2/… with literals from $matches[]
            $repl = preg_replace_callback(
                function ($m) use ($matches) {
                    if (!isset($matches[$m[1]])) { trigger_error("No capture group for '$m[0]' eval placeholder"); }
                    return addcslashes($matches[$m[1]], '\"\'\`\$\\\0'); # additionally escapes '$' and backticks
            # run the replacement expression
            return eval("return $repl;");

In essence, you just include that function in your codebase, and edit preg_replace to preg_replace_eval wherever the /e flag was used.

Pros and cons:

  • Really just tested with a few samples from Stack Overflow.
  • Does only support the easy cases (function calls, not variable lookups).
  • Contains a few more restrictions and advisory notices.
  • Will yield dislocated and less comprehensible errors for expression failures.
  • However is still a usable temporary solution and doesn't complicate a proper transition to preg_replace_callback.
  • And the license comment is just meant to deter people from overusing or spreading this too far.

Replacement code generator

Now this is somewhat redundant. But might help those users who are still overwhelmed with manually restructuring their code to preg_replace_callback. While this is effectively more time consuming, a code generator has less trouble to expand the /e replacement string into an expression. It's a very unremarkable conversion, but likely suffices for the most prevalent examples.

To use this function, edit any broken preg_replace call into preg_replace_eval_replacement and run it once. This will print out the according preg_replace_callback block to be used in its place.

 * Use once to generate a crude preg_replace_callback() substitution. Might often
 * require additional changes in the `return …;` expression. You'll also have to
 * refit the variable names for input/output obviously.
 * >>>  preg_replace_eval_replacement("/\w+/", 'strtopupper("$1")', $ignored);
function preg_replace_eval_replacement($pattern, $replacement, $subjectvar="IGNORED") {
    $pattern = preg_replace('/(\W[a-df-z]*)e([a-df-z]*)$/i', '$1$2', $pattern);
    $replacement = preg_replace_callback('/[\'\"]?(?<!\\\\)(?:[$]|\\\\)(\d+)[\'\"]?/', function ($m) { return "\$m[{$m[1]}]"; }, $replacement);
    $ve = "var_export";
    $bt = debug_backtrace(0, 1)[0];
    print "<pre><code>
    # replace preg_*() call in '$bt[file]' line $bt[line] with:
    \$OUTPUT_VAR = preg_replace_callback(
        {$ve($pattern, TRUE)},
        function (\$m) {
            return {$replacement};

Take in mind that mere copy&pasting is not programming. You'll have to adapt the generated code back to your actual input/output variable names, or usage context.

  • Specificially the $OUTPUT = assignment would have to go if the previous preg_replace call was used in an if.
  • It's best to keep temporary variables or the multiline code block structure though.

And the replacement expression may demand more readability improvements or rework.

  • For instance stripslashes() often becomes redundant in literal expressions.
  • Variable-scope lookups require a use or global reference for/within the callback.
  • Unevenly quote-enclosed "-$1-$2" capture references will end up syntactically broken by the plain transformation into "-$m[1]-$m[2].

The code output is merely a starting point. And yes, this would have been more useful as an online tool. This code rewriting approach (edit, run, edit, edit) is somewhat impractical. Yet could be more approachable to those who are accustomed to task-centric coding (more steps, more uncoveries). So this alternative might curb a few more duplicate questions.

smtp configuration for php mail

php's email() function hands the email over to a underlying mail transfer agent which is usually postfix on linux systems

so the preferred method on linux is to configure your postfix to use a relayhost, which is done by a line of

relayhost =

in /etc/postfix/

however in the OP's scenario I somehow suspect that it's a job that his hosting team should have done

ReactJS and images in public folder

We know React is SPA. Everything is rendered from the root component by expanding to appropriate HTML from JSX.

So it does not matter where you want to use the images. Best practice is to use an absolute path (with reference to public). Do not worry about relative paths.

In your case, this should work everywhere:


Calling Oracle stored procedure from C#?

This Code works well for me calling oracle stored procedure

Add references by right clicking on your project name in solution explorer >Add Reference >.Net then Add namespaces.

using System.Data.OracleClient;
using System.Data;

then paste this code in event Handler

        string str = "User ID=username;Password=password;Data Source=Test";
        OracleConnection conn = new OracleConnection(str);
        OracleCommand cmd = new OracleCommand("stored_procedure_name", conn);
        cmd.CommandType = CommandType.StoredProcedure;
        --Ad parameter list--
        cmd.Parameters.Add("parameter_name", "varchar2").Value = value;

And its Done...Happy Coding with C#

How to get all elements inside "div" that starts with a known text

Option 1: Likely fastest (but not supported by some browsers if used on Document or SVGElement) :

var elements = document.getElementById('parentContainer').children;

Option 2: Likely slowest :

var elements = document.getElementById('parentContainer').getElementsByTagName('*');

Option 3: Requires change to code (wrap a form instead of a div around it) :

// Since what you're doing looks like it should be in a form...
var elements = document.forms['parentContainer'].elements;

var matches = [];

for (var i = 0; i < elements.length; i++)
    if (elements[i].value.indexOf('q17_') == 0)

what is Segmentation fault (core dumped)?

"Segmentation fault" means that you tried to access memory that you do not have access to.

The first problem is with your arguments of main. The main function should be int main(int argc, char *argv[]), and you should check that argc is at least 2 before accessing argv[1].

Also, since you're passing in a float to printf (which, by the way, gets converted to a double when passing to printf), you should use the %f format specifier. The %s format specifier is for strings ('\0'-terminated character arrays).

How to find locked rows in Oracle

you can find the locked tables in oralce by querying with following query

   v$locked_object a ,
   v$session b,
   dba_objects c
   b.sid = a.session_id
   a.object_id = c.object_id;

How can a Javascript object refer to values in itself?

Because the statement defining obj hasn't finished, key1 doesn't exist yet. Consider this solution:

var obj = { key1: "it" };
obj.key2 = obj.key1 + ' ' + 'works!';
// obj.key2 is now 'it works!'

Print line numbers starting at zero using awk

Another option besides awk is nl which allows for options -v for setting starting value and -n <lf,rf,rz> for left, right and right with leading zeros justified. You can also include -s for a field separator such as -s "," for comma separation between line numbers and your data.

In a Unix environment, this can be done as

cat <infile> | ...other stuff... | nl -v 0 -n rz

or simply

nl -v 0 -n rz <infile>


echo "Here 
words" > words.txt

cat words.txt | nl -v 0 -n rz


000000      Here
000001      are
000002      some
000003      words

How to call a View Controller programmatically?

You can call ViewController this way, If you want with NavigationController

enter image description here

1.In current Screen : Load new screen

VerifyExpViewController *addProjectViewController = [[VerifyExpViewController alloc] init];
[self.navigationController pushViewController:addProjectViewController animated:YES];

2.1 In Loaded View : add below in .h file

@interface VerifyExpViewController : UIViewController <UINavigationControllerDelegate>

2.2 In Loaded View : add below in .m file

  @implementation VerifyExpViewController

- (void)viewDidLoad
    [super viewDidLoad];

    self.navigationController.delegate = self;
    [self setNavigationBar];
    self.navigationController.navigationBar.backgroundColor = [UIColor clearColor];
    self.navigationController.navigationBar.translucent = YES;
    [self.navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:@"B_topbar.png"] forBarMetrics:UIBarMetricsDefault];
    self.navigationController.navigationBar.titleTextAttributes = @{NSForegroundColorAttributeName: [UIColor whiteColor]};
    self.navigationItem.hidesBackButton = YES;
    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"Btn_topback.png"] style:UIBarButtonItemStylePlain target:self action:@selector(onBackButtonTap:)];
    self.navigationItem.leftBarButtonItem.tintColor = [UIColor lightGrayColor];
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"Save.png"] style:UIBarButtonItemStylePlain target:self action:@selector(onSaveButtonTap:)];
    self.navigationItem.rightBarButtonItem.tintColor = [UIColor lightGrayColor];

    [self.navigationController popViewControllerAnimated:YES];
    //todo for save button


Hope this will be useful for someone there :)

How do I automatically scroll to the bottom of a multiline text box?

This will scroll to the end of the textbox when the text is changed, but still allows the user to scroll up

outbox.SelectionStart = outbox.Text.Length;

tested on Visual Studio Enterprise 2017

Access parent's parent from javascript object

With the following code you can access the parent of the object:

var Users = function(parent) {
    this.parent = parent;
Users.prototype.guys = function(){ 
Users.prototype.girls = function(){ 

var list = {
    users : function() {
        return new Users(this);
    nameAndDestroy : function(group){ console.log(group); },
    kiss : function(group){ console.log(group); }

list.users().guys(); // should output ["test-name-and-destroy"]
list.users().girls(); // should output ["test-kiss"]

I would recommend you read about javascript Objects to get to know how you can work with Objects, it helped me a lot. I even found out about functions that I didn't even knew they existed.

Using If/Else on a data frame

Use ifelse:

frame$twohouses <- ifelse(frame$data>=2, 2, 1)
   data twohouses
1     0         1
2     1         1
3     2         2
4     3         2
5     4         2
16    0         1
17    2         2
18    1         1
19    2         2
20    0         1
21    4         2

The difference between if and ifelse:

  • if is a control flow statement, taking a single logical value as an argument
  • ifelse is a vectorised function, taking vectors as all its arguments.

The help page for if, accessible via ?"if" will also point you to ?ifelse

Pushing to Git returning Error Code 403 fatal: HTTP request failed

  1. Click on your repository
  2. On the right hand side, click on "Settings"
  3. On the left hand side option panel, click on "Collaborators"
  4. Add the person name you know in GitHub
  5. Click "Add Collaborators"

After this our "Push to Git" worked fine.

How can I access and process nested objects, arrays or JSON?

Objects and arrays has a lot of built-in methods that can help you with processing data.

Note: in many of the examples I'm using arrow functions. They are similar to function expressions, but they bind the this value lexically.

Object.keys(), Object.values() (ES 2017) and Object.entries() (ES 2017)

Object.keys() returns an array of object's keys, Object.values() returns an array of object's values, and Object.entries() returns an array of object's keys and corresponding values in a format [key, value].

const obj = {_x000D_
  a: 1_x000D_
 ,b: 2_x000D_
 ,c: 3_x000D_
console.log(Object.keys(obj)) // ['a', 'b', 'c']_x000D_
console.log(Object.values(obj)) // [1, 2, 3]_x000D_
console.log(Object.entries(obj)) // [['a', 1], ['b', 2], ['c', 3]]

Object.entries() with a for-of loop and destructuring assignment

const obj = {_x000D_
  a: 1_x000D_
 ,b: 2_x000D_
 ,c: 3_x000D_
for (const [key, value] of Object.entries(obj)) {_x000D_
  console.log(`key: ${key}, value: ${value}`)_x000D_

It's very convenient to iterate the result of Object.entries() with a for-of loop and destructuring assignment.

For-of loop lets you iterate array elements. The syntax is for (const element of array) (we can replace const with var or let, but it's better to use const if we don't intend to modify element).

Destructuring assignment lets you extract values from an array or an object and assign them to variables. In this case const [key, value] means that instead of assigning the [key, value] array to element, we assign the first element of that array to key and the second element to value. It is equivalent to this:

for (const element of Object.entries(obj)) {
  const key = element[0]
       ,value = element[1]

As you can see, destructuring makes this a lot simpler.

Array.prototype.every() and Array.prototype.some()

The every() method returns true if the specified callback function returns true for every element of the array. The some() method returns true if the specified callback function returns true for some (at least one) element.

const arr = [1, 2, 3]_x000D_
// true, because every element is greater than 0_x000D_
console.log(arr.every(x => x > 0))_x000D_
// false, because 3^2 is greater than 5_x000D_
console.log(arr.every(x => Math.pow(x, 2) < 5))_x000D_
// true, because 2 is even (the remainder from dividing by 2 is 0)_x000D_
console.log(arr.some(x => x % 2 === 0))_x000D_
// false, because none of the elements is equal to 5_x000D_
console.log(arr.some(x => x === 5))

Array.prototype.find() and Array.prototype.filter()

The find() methods returns the first element which satisfies the provided callback function. The filter() method returns an array of all elements which satisfies the provided callback function.

const arr = [1, 2, 3]_x000D_
// 2, because 2^2 !== 2_x000D_
console.log(arr.find(x => x !== Math.pow(x, 2)))_x000D_
// 1, because it's the first element_x000D_
console.log(arr.find(x => true))_x000D_
// undefined, because none of the elements equals 7_x000D_
console.log(arr.find(x => x === 7))_x000D_
// [2, 3], because these elements are greater than 1_x000D_
console.log(arr.filter(x => x > 1))_x000D_
// [1, 2, 3], because the function returns true for all elements_x000D_
console.log(arr.filter(x => true))_x000D_
// [], because none of the elements equals neither 6 nor 7_x000D_
console.log(arr.filter(x => x === 6 || x === 7))

The map() method returns an array with the results of calling a provided callback function on the array elements.

const arr = [1, 2, 3]_x000D_
console.log( => x + 1)) // [2, 3, 4]_x000D_
console.log( => String.fromCharCode(96 + x))) // ['a', 'b', 'c']_x000D_
console.log( => x)) // [1, 2, 3] (no-op)_x000D_
console.log( => Math.pow(x, 2))) // [1, 4, 9]_x000D_
console.log( // ['1', '2', '3']


The reduce() method reduces an array to a single value by calling the provided callback function with two elements.

const arr = [1, 2, 3]_x000D_
// Sum of array elements._x000D_
console.log(arr.reduce((a, b) => a + b)) // 6_x000D_
// The largest number in the array._x000D_
console.log(arr.reduce((a, b) => a > b ? a : b)) // 3

The reduce() method takes an optional second parameter, which is the initial value. This is useful when the array on which you call reduce() can has zero or one elements. For example, if we wanted to create a function sum() which takes an array as an argument and returns the sum of all elements, we could write it like that:

const sum = arr => arr.reduce((a, b) => a + b, 0)_x000D_
console.log(sum([]))     // 0_x000D_
console.log(sum([4]))    // 4_x000D_
console.log(sum([2, 5])) // 7

How to set the style -webkit-transform dynamically using JavaScript?

If you want to do it via setAttribute you would change the style attribute like so:

element.setAttribute('style','transform:rotate(90deg); -webkit-transform: rotate(90deg)') //etc

This would be helpful if you want to reset all other inline style and only set your needed style properties' values again, BUT in most cases you may not want that. That's why everybody advised to use this: = 'rotate(90deg)'; = 'rotate(90deg)';

The above is equivalent to['transform'] = 'rotate(90deg)';['-webkit-transform'] = 'rotate(90deg)';

ADB not recognising Nexus 4 under Windows 7

I had a similar problem, and none of the previous solutions worked for me, and I've just solved it by myself (after a few hours of frustration), so I'm going to share my solution.

My computer suddenly stopped recognizing any Android device I've plugged in after it installed Android Composite ADB Interface for my Nexus 4. I was not able to uninstall the driver, because any attempt to do so by Device Manager was unsuccessful (Device Manager stopped responding every time).

So I've solved it this way:

  1. Switch Windows into safe mode
  2. Uninstall Android Composite ADB Interface
  3. Install old SAMSUNG Android ADB Interface
  4. Switch Windows into normal mode
  5. Plug-in Android device (Nexus 4 in my case)
  6. Windows recognized the device as Nexus 4
  7. Install driver from android-sdk/extras/google folder
  8. Everything works again! :)

How to customize an end time for a YouTube video?

Use parameters(seconds) i.e.

Live DEMO:

Printing with "\t" (tabs) does not result in aligned columns

Building on this question, I use the following code to indent my messages:

String prefix1 = "short text:";
String prefix2 = "looooooooooooooong text:";
String msg = "indented";
* The second string begins after 40 characters. The dash means that the
* first string is left-justified.
String format = "%-40s%s%n";
System.out.printf(format, prefix1, msg);
System.out.printf(format, prefix2, msg);

This is the output:

short text:                             indented
looooooooooooooong text:                indented

This is documented in section "Flag characters" in man 3 printf.

Using pointer to char array, values in that array can be accessed?

Your should create ptr as follows:

char *ptr;

You have created ptr as an array of pointers to chars. The above creates a single pointer to a char.

Edit: complete code should be:

char *ptr;
char arr[5] = {'a','b','c','d','e'};
ptr = arr;
printf("\nvalue:%c", *(ptr+0));

Get IP address of visitors using Flask for Python

The user's IP address can be retrieved using the following snippet:

from flask import request

Iterating over ResultSet and adding its value in an ArrayList

If I've understood your problem correctly, there are two possible problems here:

  • resultset is null - I assume that this can't be the case as if it was you'd get an exception in your while loop and nothing would be output.
  • The second problem is that resultset.getString(i++) will get columns 1,2,3 and so on from each subsequent row.

I think that the second point is probably your problem here.

Lets say you only had 1 row returned, as follows:

Col 1, Col 2, Col 3 
A    ,     B,     C

Your code as it stands would only get A - it wouldn't get the rest of the columns.

I suggest you change your code as follows:

ResultSet resultset = ...;
ArrayList<String> arrayList = new ArrayList<String>(); 
while ( {                      
    int i = 1;
    while(i <= numberOfColumns) {
    System.out.println(resultset.getString("Col 1"));
    System.out.println(resultset.getString("Col 2"));
    System.out.println(resultset.getString("Col 3"));                    
    System.out.println(resultset.getString("Col n"));


To get the number of columns:

ResultSetMetaData metadata = resultset.getMetaData();
int numberOfColumns = metadata.getColumnCount();

python, sort descending dataframe with pandas

New syntax (either):

 test = df.sort_values(['one'], ascending=[False])
 test = df.sort_values(['one'], ascending=[0])

How to remove line breaks (no characters!) from the string?

Something a bit more functional (easy to use anywhere):

function strip_carriage_returns($string)
    return str_replace(array("\n\r", "\n", "\r"), '', $string);

Using PHP_EOL as the search replacement parameter is also a good idea! Kudos.

Adb install failure: INSTALL_CANCELED_BY_USER

On Xiaomi Mi5s with MIUI8.3 (Android 6) Xiaomi.EU Rom:

Settings/ Other Settings / Developer Options / Switch on: Allow USB Debug, Allow USB install and Allow USB Debug (Security options)

{Sorry for the translation, my device has spanish}

"Large data" workflows using pandas

I recently came across a similar issue. I found simply reading the data in chunks and appending it as I write it in chunks to the same csv works well. My problem was adding a date column based on information in another table, using the value of certain columns as follows. This may help those confused by dask and hdf5 but more familiar with pandas like myself.

def addDateColumn():
"""Adds time to the daily rainfall data. Reads the csv as chunks of 100k 
   rows at a time and outputs them, appending as needed, to a single csv. 
   Uses the column of the raster names to get the date.
    df = pd.read_csv(pathlist[1]+"CHIRPS_tanz.csv", iterator=True, 
                     chunksize=100000) #read csv file as 100k chunks

    '''Do some stuff'''

    count = 1 #for indexing item in time list 
    for chunk in df: #for each 100k rows
        newtime = [] #empty list to append repeating times for different rows
        toiterate = chunk[chunk.columns[2]] #ID of raster nums to base time
        while count <= toiterate.max():
            for i in toiterate: 
                if i ==count:
        print "Finished", str(chunknum), "chunks"
        chunk["time"] = newtime #create new column in dataframe based on time
        outname = "CHIRPS_tanz_time2.csv"
        #append each output to same csv, using no header
        chunk.to_csv(pathlist[2]+outname, mode='a', header=None, index=None)

Handle Button click inside a row in RecyclerView

Just wanted to add another solution if you already have a recycler touch listener and want to handle all of the touch events in it rather than dealing with the button touch event separately in the view holder. The key thing this adapted version of the class does is return the button view in the onItemClick() callback when it's tapped, as opposed to the item container. You can then test for the view being a button, and carry out a different action. Note, long tapping on the button is interpreted as a long tap on the whole row still.

public class RecyclerItemClickListener implements RecyclerView.OnItemTouchListener
    public static interface OnItemClickListener
        public void onItemClick(View view, int position);
        public void onItemLongClick(View view, int position);

    private OnItemClickListener mListener;
    private GestureDetector mGestureDetector;

    public RecyclerItemClickListener(Context context, final RecyclerView recyclerView, OnItemClickListener listener)
        mListener = listener;

        mGestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener()
            public boolean onSingleTapUp(MotionEvent e)
                // Important: x and y are translated coordinates here
                final ViewGroup childViewGroup = (ViewGroup) recyclerView.findChildViewUnder(e.getX(), e.getY());

                if (childViewGroup != null && mListener != null) {
                    final List<View> viewHierarchy = new ArrayList<View>();
                    // Important: x and y are raw screen coordinates here
                    getViewHierarchyUnderChild(childViewGroup, e.getRawX(), e.getRawY(), viewHierarchy);

                    View touchedView = childViewGroup;
                    if (viewHierarchy.size() > 0) {
                        touchedView = viewHierarchy.get(0);
                    mListener.onItemClick(touchedView, recyclerView.getChildPosition(childViewGroup));
                    return true;

                return false;

            public void onLongPress(MotionEvent e)
                View childView = recyclerView.findChildViewUnder(e.getX(), e.getY());

                if(childView != null && mListener != null)
                    mListener.onItemLongClick(childView, recyclerView.getChildPosition(childView));

    public void getViewHierarchyUnderChild(ViewGroup root, float x, float y, List<View> viewHierarchy) {
        int[] location = new int[2];
        final int childCount = root.getChildCount();

        for (int i = 0; i < childCount; ++i) {
            final View child = root.getChildAt(i);
            final int childLeft = location[0], childRight = childLeft + child.getWidth();
            final int childTop = location[1], childBottom = childTop + child.getHeight();

            if (child.isShown() && x >= childLeft && x <= childRight && y >= childTop && y <= childBottom) {
                viewHierarchy.add(0, child);
            if (child instanceof ViewGroup) {
                getViewHierarchyUnderChild((ViewGroup) child, x, y, viewHierarchy);

    public boolean onInterceptTouchEvent(RecyclerView view, MotionEvent e)

        return false;

    public void onTouchEvent(RecyclerView view, MotionEvent motionEvent){}

    public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {


Then using it from activity / fragment:


    public RecyclerItemClickListener createItemClickListener(final RecyclerView recyclerView) {
        return new RecyclerItemClickListener (context, recyclerView, new RecyclerItemClickListener.OnItemClickListener() {
            public void onItemClick(View view, int position) {
                if (view instanceof AppCompatButton) {
                    // ... tapped on the button, so go do something
                } else {
                    // ... tapped on the item container (row), so do something different

            public void onItemLongClick(View view, int position) {

JPG vs. JPEG image formats

No difference at all.

I personally prefer having 3 letters extensions, but you might prefer having the full name.
It's pure aestetics (personal taste), nothing else.
The format doesn't change.

You can rename the jpeg files into jpg (or vice versa) an nothing changes: they will open in your picture viewer.

By opening both a JPG and a JPEG file with an hex editor, you will notice that they share the very same heading information.

C# generics syntax for multiple type parameter constraints

void foo<TOne, TTwo>() 
   where TOne : BaseOne
   where TTwo : BaseTwo

More info here:

"undefined" function declared in another file?

If you're using go run, do go run *.go. It will automatically find all go files in the current working directory, compile and then run your main function.

Do something if screen width is less than 960 px

Try this code

if ($(window).width() < 960) {
 alert('width is less than 960px');
else {
 alert('More than 960');

   if ($(window).width() < 960) {_x000D_
     alert('width is less than 960px');_x000D_
    else {_x000D_
     alert('More than 960');_x000D_
<script src=""></script>

CSS: fixed position on x-axis but not y?

If your block is originally positioned as static, you may want to try this

$(window).on('scroll', function () {_x000D_
  var $w = $(window);_x000D_
  $('.position-fixed-x').css('left', $w.scrollLeft());_x000D_
  $('.position-fixed-y').css('top', $w.scrollTop());_x000D_
.container {_x000D_
  width: 1000px;_x000D_
.position-fixed-x {_x000D_
  position: relative; _x000D_
.position-fixed-y {_x000D_
  position: relative;_x000D_
.blue-box {_x000D_
  width: 50px;_x000D_
  height: 50px;_x000D_
.red-box {_x000D_
  background: red;_x000D_
  width: 50px;_x000D_
  height: 50px;_x000D_
<script src=""></script>_x000D_
<div class="container">_x000D_
<div class="position-fixed-y red-box">_x000D_
The pattern of base pairs in the DNA double helix encodes the instructions for building the proteins necessary to construct an entire organism. DNA, or deoxyribonucleic acid, is found within most cells of an organism, and most organisms have their own unique DNA code. One exception to this is cloned organisms, which have the same exact DNA code as their parents do._x000D_
<div class="position-fixed-x blue-box">_x000D_
DNA strands are composed of millions of sub-units, called nucleotides. Each nucleotide contains a 5-carbon sugar, a phosphate group and a nitrogen base. There are four different variations of the nitrogen base group, responsible for all of the variation between two different DNA strands. The four different variations are called adenine, guanine, cytosine and thymine, but they are typically abbreviated and only referred to by their first letter. The sequence of these different nitrogen bases makes up the code of the DNA._x000D_
The DNA strand splits in two, and forms two different DNA strands during cell replication. However, sometimes this process is not perfect, and mistakes occur. These mistakes may change the way an organism is constructed or functions. When this happens, it is called a mutation. These mutations can be helpful or harmful, and they are usually passed on to the organism’s offspring._x000D_
 The traits of a living thing depend on the complex mixture of interacting components inside it. Proteins do much of the chemical work inside cells, so they largely determine what those traits are. But those proteins owe their existence to the DNA (deoxyribonucleic acid), so that is where we must look for the answer._x000D_
The easiest way to understand how DNA is organized is to start with its basic building blocks. DNA consists of four different sugars that interact with each other in specific ways. These four sugars are called nucleotide bases and have the names adenine (A), thymine (T), cytosine (C) and guanine (G). Think of these four bases as letters in an alphabet, the alphabet of life!_x000D_
If we hook up these nucleotides into a sequence--for example, GATCATCCG--we now have a little piece of DNA, or a very short word. A much longer piece of DNA can therefore be the equivalent of different words connected to make a sentence, or gene, that describes how to build a protein. And a still longer piece of DNA could contain information about when that protein should be made. All the DNA in a cell gives us enough words and sentences to serve as a master description or blueprint for a human (or an animal, a plant, or a microorganism)._x000D_
Of course, the details are a little more complicated than that! In practice, active stretches of DNA must be copied as a similar message molecule called RNA. The words in the RNA then need to be "read" to produce the proteins, which are themselves stretches of words made up of a different alphabet, the amino acid alphabet. Nobel laureates Linus Pauling, who discerned the structure of proteins, and James Watson and Francis Crick, who later deciphered the helical structure of DNA, helped us to understand this "Central Dogma" of heredity--that the DNA code turns into an RNA message that has the ability to organize 20 amino acids into a complex protein: DNA -> RNA -> Protein._x000D_
To understand how this all comes together, consider the trait for blue eyes. DNA for a blue-eyes gene is copied as a blue-eyes RNA message. That message is then translated into the blue protein pigments found in the cells of the eye. For every trait we have--eye color, skin color and so on--there is a gene or group of genes that controls the trait by producing first the message and then the protein. Sperm cells and eggs cells are specialized to carry DNA in such a way that, at fertilization, a new individual with traits from both its mother and father is created._x000D_

How do I compile and run a program in Java on my Mac?

I will give you steps to writing and compiling code. Use this example:

 public class Paycheck {
    public static void main(String args[]) {
        double amountInAccount;
        amountInAccount = 128.57;
        System.out.print("You earned $");
        System.out.println(" at work today.");
  1. Save the code as
  2. Go to terminal and type cd Desktop
  3. Type javac
  4. Type java Paycheck
  5. Enjoy your program!

How is CountDownLatch used in Java Multithreading?

package practice;

import java.util.concurrent.CountDownLatch;

public class CountDownLatchExample {

    public static void main(String[] args) throws InterruptedException {
        CountDownLatch c= new CountDownLatch(3);  // need to decrements the count (3) to zero by calling countDown() method so that main thread will wake up after calling await() method 
        Task t = new Task(c);
        Task t1 = new Task(c);
        Task t2 = new Task(c);
        c.await(); // when count becomes zero main thread will wake up 
        System.out.println("This will print after count down latch count become zero");

class Task extends Thread{
    CountDownLatch c;

    public Task(CountDownLatch c) {
        this.c = c;

    public void run() {
        try {
            c.countDown();   // each thread decrement the count by one 
        } catch (InterruptedException e) {

How can I get new selection in "select" in Angular 2?

use selectionChange in angular 6 and above. example (selectionChange)= onChange($event.value)

use "netsh wlan set hostednetwork ..." to create a wifi hotspot and the authentication can't work correctly

Problem solved.

Just drop down status bar, touch Choose input method, then change to another input method, type the password again. And everything is OK.

So weird...

Solution from a Chinese BBS. Thanks for the answer's author and all above who try to provide a solution, thanks!

Dynamically updating plot in matplotlib

I know I'm late to answer this question, but for your issue you could look into the "joystick" package. I designed it for plotting a stream of data from the serial port, but it works for any stream. It also allows for interactive text logging or image plotting (in addition to graph plotting). No need to do your own loops in a separate thread, the package takes care of it, just give the update frequency you wish. Plus the terminal remains available for monitoring commands while plotting. See or (use pip install joystick to install)

Just replace np.random.random() by your real data point read from the serial port in the code below:

import joystick as jk
import numpy as np
import time

class test(jk.Joystick):
    # initialize the infinite loop decorator
    _infinite_loop = jk.deco_infinite_loop()

    def _init(self, *args, **kwargs):
        Function called at initialization, see the doc
        self._t0 = time.time()  # initialize time
        self.xdata = np.array([self._t0])  # time x-axis
        self.ydata = np.array([0.0])  # fake data y-axis
        # create a graph frame
        self.mygraph = self.add_frame(jk.Graph(name="test", size=(500, 500), pos=(50, 50), fmt="go-", xnpts=10000, xnptsmax=10000, xylim=(None, None, 0, 1)))

    def _generate_data(self):  # function looped every 0.2 second to read or produce data
        Loop starting with the simulation start, getting data and
    pushing it to the graph every 0.2 seconds
        # concatenate data on the time x-axis
        self.xdata = jk.core.add_datapoint(self.xdata, time.time(), xnptsmax=self.mygraph.xnptsmax)
        # concatenate data on the fake data y-axis
        self.ydata = jk.core.add_datapoint(self.ydata, np.random.random(), xnptsmax=self.mygraph.xnptsmax)
        self.mygraph.set_xydata(t, self.ydata)

t = test()

Copying files to a container with Docker Compose


      - /dir/on/host:/var/www/html

if /dir/on/host doesn't exist, it is created on the host and the empty content is mounted in the container at /var/www/html. Whatever content you had before in /var/www/html inside the container is inaccessible, until you unmount the volume; the new mount is hiding the old content.

Filtering a list based on a list of booleans

With python 3 you can use list_a[filter] to get True values. To get False values use list_a[~filter]

How to determine whether a given Linux is 32 bit or 64 bit?

lscpu will list out these among other information regarding your CPU:

Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit

Read all contacts' phone numbers in android

You can read all of the telephone numbers associated with a contact in the following manner:

Uri personUri = ContentUris.withAppendedId(People.CONTENT_URI, personId);
Uri phonesUri = Uri.withAppendedPath(personUri, People.Phones.CONTENT_DIRECTORY);
String[] proj = new String[] {Phones._ID, Phones.TYPE, Phones.NUMBER, Phones.LABEL}
Cursor cursor = contentResolver.query(phonesUri, proj, null, null, null);

Please note that this example (like yours) uses the deprecated contacts API. From eclair onwards this has been replaced with the ContactsContract API.

ArrayBuffer to base64 encoded string

var blob = new Blob([arrayBuffer])

var reader = new FileReader();
reader.onload = function(event){
   var base64 =


Display a tooltip over a button using Windows Forms

Using the form designer:

  • Drag the ToolTip control from the Toolbox, onto the form.
  • Select the properties of the control you want the tool tip to appear on.
  • Find the property 'ToolTip on toolTip1' (the name may not be toolTip1 if you changed it's default name).
  • Set the text of the property to the tool tip text you would like to display.

You can set also the tool tip programatically using the following call:

this.toolTip1.SetToolTip(this.targetControl, "My Tool Tip");

System.Net.WebException: The remote name could not be resolved:

It's probably caused by a local network connectivity issue (but also a DNS error is possible). Unfortunately HResult is generic, however you can determine the exact issue catching HttpRequestException and then inspecting InnerException: if it's a WebException then you can check the WebException.Status property, for example WebExceptionStatus.NameResolutionFailure should indicate a DNS resolution problem.

It may happen, there isn't much you can do.

What I'd suggest to always wrap that (network related) code in a loop with a try/catch block (as also suggested here for other fallible operations). Handle known exceptions, wait a little (say 1000 msec) and try again (for say 3 times). Only if failed all times then you can quit/report an error to your users. Very raw example like this:

private const int NumberOfRetries = 3;
private const int DelayOnRetry = 1000;

public static async Task<HttpResponseMessage> GetFromUrlAsync(string url) {
    using (var client = new HttpClient()) {
        for (int i=1; i <= NumberOfRetries; ++i) {
            try {
                return await client.GetAsync(url); 
            catch (Exception e) when (i < NumberOfRetries) {
                await Task.Delay(DelayOnRetry);

How do I skip an iteration of a `foreach` loop?

Use the continue statement:

foreach(object number in mycollection) {
     if( number < 0 ) {

How to create a circular ImageView in Android?

I too needed a rounded ImageView, I used the below code, you can modify it accordingly:

import android.content.Context;
import android.util.AttributeSet;
import android.widget.ImageView;

public class RoundedImageView extends ImageView {

    public RoundedImageView(Context context) {

    public RoundedImageView(Context context, AttributeSet attrs) {
        super(context, attrs);

    public RoundedImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);

    protected void onDraw(Canvas canvas) {

        Drawable drawable = getDrawable();

        if (drawable == null) {

        if (getWidth() == 0 || getHeight() == 0) {
        Bitmap b = ((BitmapDrawable) drawable).getBitmap();
        Bitmap bitmap = b.copy(Bitmap.Config.ARGB_8888, true);

        int w = getWidth();
        int h = getHeight();

        Bitmap roundBitmap = getCroppedBitmap(bitmap, w);
        canvas.drawBitmap(roundBitmap, 0, 0, null);


    public static Bitmap getCroppedBitmap(Bitmap bmp, int radius) {
        Bitmap sbmp;

        if (bmp.getWidth() != radius || bmp.getHeight() != radius) {
            float smallest = Math.min(bmp.getWidth(), bmp.getHeight());
            float factor = smallest / radius;
            sbmp = Bitmap.createScaledBitmap(bmp,
                    (int) (bmp.getWidth() / factor),
                    (int) (bmp.getHeight() / factor), false);
        } else {
            sbmp = bmp;

        Bitmap output = Bitmap.createBitmap(radius, radius, Config.ARGB_8888);
        Canvas canvas = new Canvas(output);

        final String color = "#BAB399";
        final Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, radius, radius);

        canvas.drawARGB(0, 0, 0, 0);
        canvas.drawCircle(radius / 2 + 0.7f, radius / 2 + 0.7f,
                radius / 2 + 0.1f, paint);
        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
        canvas.drawBitmap(sbmp, rect, rect, paint);

        return output;


Android Studio - How to increase Allocated Heap Size

Had this Xms and Xmx memory low issue happen to me any time I was working with the XML. I also tried increasing this memory, only to find that it just took a little longer for it to happen again.

After getting very frustrated and almost deciding to convert all my current projects back over to Eclipse, which I did not want to do, I figured out what was causing it and was able to repeat this failure and prevent it every time.

While editing the XML in (Text view), and using the "Preview" render view, this causes the loss of memory, every time. Turning off "Preview" and using the Design tab to render the screen only, I am able to use Android Studio all day long, with no crash.

I wish this could be fixed for good, because it would be very nice to use the "Preview" render while editing the XML, however I am glad I can keep using Android Studio.

Opening a remote machine's Windows C drive

By default, Windows makes the root of each drive available (provided you've got Administrator privileges) as (e.g.) \\server\c$. These are known as Administrative Shares.

How do I find out which keystore was used to sign an app?

There are many freewares to examine the certificates and key stores such as KeyStore Explorer.

Unzip the apk and open the META-INF/?.RSA file. ? shall be CERT or ANDROID or may be something else. It will display all the information associated with your apk.

Execution time of C program

(All answers here are lacking, if your sysadmin changes the systemtime, or your timezone has differing winter- and sommer-times. Therefore...)

On linux use: clock_gettime(CLOCK_MONOTONIC_RAW, &time_variable); It's not affected if the system-admin changes the time, or you live in a country with winter-time different from summer-time, etc.

#include <stdio.h>
#include <time.h>

#include <unistd.h> /* for sleep() */

int main() {
    struct timespec begin, end;
    clock_gettime(CLOCK_MONOTONIC_RAW, &begin);

    sleep(1);      // waste some time

    clock_gettime(CLOCK_MONOTONIC_RAW, &end);

    printf ("Total time = %f seconds\n",
            (end.tv_nsec - begin.tv_nsec) / 1000000000.0 +
            (end.tv_sec  - begin.tv_sec));


man clock_gettime states:

              Clock  that  cannot  be set and represents monotonic time since some unspecified starting point.  This clock is not affected by discontinuous jumps in the system time
              (e.g., if the system administrator manually changes the clock), but is affected by the incremental adjustments performed by adjtime(3) and NTP.

Angular2 : Can't bind to 'formGroup' since it isn't a known property of 'form'

Don't use userForm = new FormGroup()

Use form = new FormGroup() instead.

And in the form use <form [formGroup]="form"> ...</form>. It works for me with angular 6

npm ERR! network getaddrinfo ENOTFOUND

Step 1: Set the proxy npm set proxy http://username:password@companyProxy:8080

npm set https-proxy http://username:password@companyProxy:8080

npm config set strict-ssl false -g

NOTES: No special characters in password except @ allowed.

Shared folder between MacOSX and Windows on Virtual Box


4+ years later after the original reply in 2015, now offers an official user manual in both html and pdf formats, which effectively deprecates the previous version of this answer:

  • Step 3 (Guest Additions) mentioned in this response as well as several others, is discussed in great detail in manual sections 4.1 and 4.2
  • Step 1 (Shared Folders Setting in VirtualBox Manager) is discussed in section 4.3

Original Answer

Because there isn't an official answer yet and I literally just did this for my OS X/WinXP install, here's what I did:

  1. VirtualBox Manager: Open the Shared Folders setting and click the '+' icon to add a new folder. Then, populate the Folder Path (or use the drop-down to navigate) with the folder you want shared and make sure "Auto-Mount" and "Make Permanent" are checked.
  2. Boot Windows
  3. Once Windows is running, goto the Devices menu (at the top of the VirtualBox Manager window) and select "Insert Guest Additions CD Image...". Cycle through the prompts and once you finish installing, let it reboot.
  4. After Windows reboots, your new drive should show up as a Network Drive in Windows Explorer.

Hope that helps.

Working around MySQL error "Deadlock found when trying to get lock; try restarting transaction"

If you are using InnoDB or any row-level transactional RDBMS, then it is possible that any write transaction can cause a deadlock, even in perfectly normal situations. Larger tables, larger writes, and long transaction blocks will often increase the likelihood of deadlocks occurring. In your situation, it's probably a combination of these.

The only way to truly handle deadlocks is to write your code to expect them. This generally isn't very difficult if your database code is well written. Often you can just put a try/catch around the query execution logic and look for a deadlock when errors occur. If you catch one, the normal thing to do is just attempt to execute the failed query again.

I highly recommend you read this page in the MySQL manual. It has a list of things to do to help cope with deadlocks and reduce their frequency.

Changing background colour of tr element on mouseover

<tr>s themselves are very hard to access with CSS, try tr:hover td {background:#000}

HTML input time in 24 format

In my case, it is taking time in AM and PM but sending data in 00-24 hours format to the server on form submit. and when use that DB data in its value then it will automatically select the appropriate AM or PM to edit form value.

Blur effect on a div element

Try using this library:

That should do it for ya.

Gitignore not working

In my case it was a blank space at the beginning of the file which showed up clearly when I opened the file in Notepad, wasn't obvious in Visual Studio Code.

How to schedule a periodic task in Java?

If you want to stick with java.util.Timer, you can use it to schedule at large time intervals. You simply pass in the period you are shooting for. Check the documentation here.

Comparing two strings in C?

You need to use strcmp:

strcmp(namet2, nameIt2)

How do I make a fully statically linked .exe with Visual Studio Express 2005?

For the C-runtime go to the project settings, choose C/C++ then 'Code Generation'. Change the 'runtime library' setting to 'multithreaded' instead of 'multithreaded dll'.

If you are using any other libraries you may need to tell the linker to ignore the dynamically linked CRT explicitly.

How to convert any Object to String?

I've written a few methods for convert by Gson library and java 1.8 .
thay are daynamic model for convert.

string to object

object to string

List to string

string to List

HashMap to String

String to JsonObj

public static String convertMapToString(Map<String, String> data) {
    //convert Map  to String
    return new GsonBuilder().setPrettyPrinting().create().toJson(data);
public static <T> List<T> convertStringToList(String strListObj) {
    //convert string json to object List
    return new Gson().fromJson(strListObj, new TypeToken<List<Object>>() {
public static <T> T convertStringToObj(String strObj, Class<T> classOfT) {
    //convert string json to object
    return new Gson().fromJson(strObj, (Type) classOfT);

public static JsonObject convertStringToJsonObj(String strObj) {
    //convert string json to object
    return new Gson().fromJson(strObj, JsonObject.class);

public static <T> String convertListObjToString(List<T> listObj) {
    //convert object list to string json for
    return new Gson().toJson(listObj, new TypeToken<List<T>>() {

public static String convertObjToString(Object clsObj) {
    //convert object  to string json
    String jsonSender = new Gson().toJson(clsObj, new TypeToken<Object>() {
    return jsonSender;

How to get current domain name in ASP.NET

Here is a quick easy way to just get the name of the url.

            var urlHost = HttpContext.Current.Request.Url.Host;

            var xUrlHost = urlHost.Split('.');
            foreach(var thing in xUrlHost)
                if(thing != "www" && thing != "com")
                    urlHost = thing;

How to get HttpContext.Current in ASP.NET Core?

There is a solution to this if you really need a static access to the current context. In Startup.Configure(….)

app.Use(async (httpContext, next) =>
    CallContext.LogicalSetData("CurrentContextKey", httpContext);
        await next();

And when you need it you can get it with :

HttpContext context = CallContext.LogicalGetData("CurrentContextKey") as HttpContext;

I hope that helps. Keep in mind this workaround is when you don’t have a choice. The best practice is to use de dependency injection.

Entity Framework (EF) Code First Cascade Delete for One-to-Zero-or-One relationship

You could also disable the cascade delete convention in global scope of your application by doing this:


How do I uninstall a package installed using npm link?

The package can be uninstalled using the same uninstall or rm command that can be used for removing installed packages. The only thing to keep in mind is that the link needs to be uninstalled globally - the --global flag needs to be provided.

In order to uninstall the globally linked foo package, the following command can be used (using sudo if necessary, depending on your setup and permissions)

sudo npm rm --global foo

This will uninstall the package.

To check whether a package is installed, the npm ls command can be used:

npm ls --global foo

json_decode returns NULL after webservice call

You should try out json_last_error_msg(). It will give you the error message and tell you what is wrong. It was introduced in PHP 5.5.

$foo = "{"action":"set","user":"123123123123","status":"OK"}";
$data = json_decode($foo, true);
if($data == null) {
    throw new Exception('Decoding JSON failed with the following message: '
                             . json_last_error_msg());

// ... JSON decode was good => Let's use the data

Overriding !important style

If you want to update / add single style in DOM Element style attribute you can use this function:

function setCssTextStyle(el, style, value) {
  var result = RegExp("(?:[;\\s]|^)(" +
      style.replace("-", "\\-") + "\\s*:(.*?)(;|$))")),
  if (result) {
    idx = result.index + result[0].indexOf(result[1]); =, idx) +
      style + ": " + value + ";" + + result[1].length);
  } else { += " " + style + ": " + value + ";";

style.cssText is supported for all major browsers.

Use case example:

var elem = document.getElementById("elementId");
setCssTextStyle(elem, "margin-top", "10px !important");

Here is link to demo

How to verify static void method has been called with power mockito

Thou the above answer is widely accepted and well documented, I found some of the reason to post my answer here :-

    doNothing().when(InternalUtils.class); //This is the preferred way
                                           //to mock static void methods.
    InternalUtils.sendEmail(anyString(), anyString(), anyString(), anyString());

Here, I dont understand why we are calling InternalUtils.sendEmail ourself. I will explain in my code why we don't need to do that.


So, we have mocked the class which is fine. Now, lets have a look how we need to verify the sendEmail(/..../) method.

public class InternalServiceTest {

    private InternalService.Order order;

    private InternalService internalService;

    public void setup() {
        internalService = new InternalService();

    public void processOrder() throws Exception {



        InternalService.InternalUtils.sendEmail(anyString(), any(String[].class), anyString(), anyString());


These two lines is where the magic is, First line tells the PowerMockito framework that it needs to verify the class it statically mocked. But which method it need to verify ?? Second line tells which method it needs to verify.

InternalService.InternalUtils.sendEmail(anyString(), any(String[].class), anyString(), anyString());

This is code of my class, sendEmail api twice.

public class InternalService {

    public void processOrder(Order order) {
        if (order.isSuccessful()) {
            InternalUtils.sendEmail("", new String[1], "", "");
            InternalUtils.sendEmail("", new String[1], "", "");

    public static class InternalUtils{

        public static void sendEmail(String from, String[]  to, String msg, String body){



    public class Order{

        public boolean isSuccessful(){
            return true;



As it is calling twice you just need to change the verify(times(2))... that's all.

java.lang.IllegalStateException: Cannot (forward | sendRedirect | create session) after response has been committed

After return forward method you can simply do this:

return null;

It will break the current scope.

How to get current time and date in Android

current time and date in android with the format

Calendar c = Calendar.getInstance();
System.out.println("Current dateTime => " + c.getTime());
SimpleDateFormat df = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss a");
String formattedDate = df.format(c.getTime());
System.out.println("Format dateTime => " + formattedDate);


I/System.out: Current dateTime => Wed Feb 26 02:58:17 GMT+05:30 2020 
I/System.out: Format dateTime => 26-02-2020 02:58:17 AM

How can I tell which button was clicked in a PHP form submit?

With an HTML form like:

<input type="submit" name="btnSubmit" value="Save Changes" />
<input type="submit" name="btnDelete" value="Delete" />

The PHP code to use would look like:

    // Something posted

    if (isset($_POST['btnDelete'])) {
        // btnDelete
    } else {
        // Assume btnSubmit

You should always assume or default to the first submit button to appear in the form HTML source code. In practice, the various browsers reliably send the name/value of a submit button with the post data when:

  1. The user literally clicks the submit button with the mouse or pointing device
  2. Or there is focus on the submit button (they tabbed to it), and then the Enter key is pressed.

Other ways to submit a form exist, and some browsers/versions decide not to send the name/value of any submit buttons in some of these situations. For example, many users submit forms by pressing the Enter key when the cursor/focus is on a text field. Forms can also be submitted via JavaScript, as well as some more obscure methods.

It's important to pay attention to this detail, otherwise you can really frustrate your users when they submit a form, yet "nothing happens" and their data is lost, because your code failed to detect a form submission, because you did not anticipate the fact that the name/value of a submit button may not be sent with the post data.

Also, the above advice should be used for forms with a single submit button too because you should always assume a default submit button.

I'm aware that the Internet is filled with tons of form-handler tutorials, and almost of all them do nothing more than check for the name and value of a submit button. But, they're just plain wrong!

Rails - passing parameters in link_to

First of all, link_to is a html tag helper, its second argument is the url, followed by html_options. What you would like is to pass account_id as a url parameter to the path. If you have set up named routes correctly in routes.rb, you can use path helpers.

link_to "+ Service", new_my_service_path(:account_id =>

I think the best practice is to pass model values as a param nested within :

link_to "+ Service", new_my_service_path(:my_service => { :account_id => })

# my_services_controller.rb
def new
  @my_service =[:my_service])

And you need to control that account_id is allowed for 'mass assignment'. In rails 3 you can use powerful controls to filter valid params within the controller where it belongs. I highly recommend.

Also note that if account_id is not freely set by the user (e.g., a user can only submit a service for the own single account_id, then it is better practice not to send it via the request, but set it within the controller by adding something like:

@my_service.account_id = current_user.account_id 

You can surely combine the two if you only allow users to create service on their own account, but allow admin to create anyone's by using roles in attr_accessible.

hope this helps

Convert dictionary to bytes and back again python?

If you need to convert the dictionary to binary, you need to convert it to a string (JSON) as described in the previous answer, then you can convert it to binary.

For example:

my_dict = {'key' : [1,2,3]}

import json
def dict_to_binary(the_dict):
    str = json.dumps(the_dict)
    binary = ' '.join(format(ord(letter), 'b') for letter in str)
    return binary

def binary_to_dict(the_binary):
    jsn = ''.join(chr(int(x, 2)) for x in the_binary.split())
    d = json.loads(jsn)  
    return d

bin = dict_to_binary(my_dict)
print bin

dct = binary_to_dict(bin)
print dct

will give the output

1111011 100010 1101011 100010 111010 100000 1011011 110001 101100 100000 110010 101100 100000 110011 1011101 1111101

{u'key': [1, 2, 3]}

Python: Find in list

Another alternative: you can check if an item is in a list with if item in list:, but this is order O(n). If you are dealing with big lists of items and all you need to know is whether something is a member of your list, you can convert the list to a set first and take advantage of constant time set lookup:

my_set = set(my_list)
if item in my_set:  # much faster on average than using a list
    # do something

Not going to be the correct solution in every case, but for some cases this might give you better performance.

Note that creating the set with set(my_list) is also O(n), so if you only need to do this once then it isn't any faster to do it this way. If you need to repeatedly check membership though, then this will be O(1) for every lookup after that initial set creation.

Vim 80 column layout concerns

Well, looking at the :help columns, it's not really being made to mess with.

In console, it's usually determined by console setting (i.e. it's detected automatically) ; in GUI, it determines (and is determined by) the width of the gvim windows.

So normally you just let consoles and window managers doing their jobs by commented out the set columns

I am not sure what you mean by "see and anticipate line overflow". If you want EOL to be inserted roughly column 80, use either set textwidth or set wrapmargin; if you just want soft wrap (i.e. line is wrapped, but no actual EOL), then play with set linebreak and set showbreak.

How to pop an alert message box using PHP?

PHP renders HTML and Javascript to send to the client's browser. PHP is a server-side language. This is what allows it do things like INSERT something into a database on the server.

But an alert is rendered by the browser of the client. You would have to work through javascript to get an alert.

React: why child component doesn't update when prop changes

You should use setState function. If not, state won't save your change, no matter how you use forceUpdate.

Container {
    handleEvent= () => { // use arrow function
        // = 123
        //You should use setState to set value like this:
        this.setState({foo: {bar: 123}});

    render() {
        return <Child bar={} />
    Child {
        render() {
            return <div>{}</div>

Your code seems not valid. I can not test this code.

How to fix error "ERROR: Command errored out with exit status 1: python." when trying to install django-heroku using pip

You need to add the package containing the executable pg_config.

A prior answer should have details you need: pg_config executable not found

Check if string matches pattern

import re
pattern = re.compile("^([A-Z][0-9]+)+$")

How to change Windows 10 interface language on Single Language version

You can download language pack and use "Install or Uninstall display languages" wizard. To do this:

  • Press Win+R, paste lpksetup and press Enter
  • Wizard will appear on the screen
  • Click the Install display languages button
  • In the next page of the wizard, click Browse and pick the *.cab file of the MUI language you downloaded
  • Click the Next button to install language

How to adjust layout when soft keyboard appears

Add this line into Manifiest File:


How to run a stored procedure in oracle sql developer?

-- If no parameters need to be passed to a procedure, simply:


Node.js – events js 72 throw er unhandled 'error' event

Check your terminal it happen only when you have your application running on another terminal..

The port is already listening..

"com.jcraft.jsch.JSchException: Auth fail" with working passwords

Tracing the root cause, i finally found that the public key of type dsa is not added to the authorized keys on remote server. Appending the same worked for me.

The ssh was working with rsa key, causing me to look back in my code.

thanks everyone.

What is the difference between Nexus and Maven?

This has a good general description:

Let me make a few statement that can put the difference in focus:

  1. We migrated our code base from Ant to Maven

  2. All 3rd party librairies have been uploaded to Nexus. Maven is using Nexus as a source for libraries.

  3. Basic functionalities of a repository manager like Sonatype are:

    • Managing project dependencies,
    • Artifacts & Metadata,
    • Proxying external repositories
    • and deployment of packaged binaries and JARs to share those artifacts with other developers and end-users.

anaconda update all possible packages?

Imagine the dependency graph of packages, when the number of packages grows large, the chance of encountering a conflict when upgrading/adding packages is much higher. To avoid this, simply create a new environment in Anaconda.

Be frugal, install only what you need. For me, I installed the following packages in my new environment:

  • pandas
  • scikit-learn
  • matplotlib
  • notebook
  • keras

And I have 84 packages in total. using a form to insert data into an sql server table

There are tons of sample code online as to how to do this.

Here is just one example of how to do this:

you define the text boxes between the following tag:

<form id="form1" runat="server"> 

you create your textboxes and define them to runat="server" like so:

<asp:TextBox ID="TxtName" runat="server"></asp:TextBox>

define a button to process your logic like so (notice the onclick):

<asp:Button ID="Button1" runat="server" Text="Save" onclick="Button1_Click" />

in the code behind, you define what you want the server to do if the user clicks on the button by defining a method named

protected void Button1_Click(object sender, EventArgs e)

or you could just double click the button in the design view.

Here is a very quick sample of code to insert into a table in the button click event (codebehind)

protected void Button1_Click(object sender, EventArgs e)
   string name = TxtName.Text; // Scrub user data

   string connString = ConfigurationManager.ConnectionStrings["yourconnstringInWebConfig"].ConnectionString;
   SqlConnection conn = null;
          conn = new SqlConnection(connString);

          using(SqlCommand cmd = new SqlCommand())
                 cmd.Conn = conn;
                 cmd.CommandType = CommandType.Text;
                 cmd.CommandText = "INSERT INTO dummyTable(name) Values (@var)";
                 cmd.Parameters.AddWithValue("@var", name);
                 int rowsAffected = cmd.ExecuteNonQuery();
                 if(rowsAffected ==1)
                        //Success notification
                        //Error notification
   catch(Exception ex)
          //log error 
          //display friendly error to user
                 //cleanup connection i.e close 

angular-cli where is webpack.config.js file - new angular6 does not support ng eject

With Angular CLI 6 you need to use builders as ng eject is deprecated and will soon be removed in 8.0. That's what it says when I try to do an ng eject

enter image description here

You can use angular-builders package ( to provide your custom webpack config.

I have tried to summarize all in a single blog post on my blog - How to customize build configuration with custom webpack config in Angular CLI 6

but essentially you add following dependencies -

  "devDependencies": {
    "@angular-builders/custom-webpack": "^7.0.0",
    "@angular-builders/dev-server": "^7.0.0",
    "@angular-devkit/build-angular": "~0.11.0",

In angular.json make following changes -

  "architect": {
    "build": {
      "builder": "@angular-builders/custom-webpack:browser",
      "options": {
        "customWebpackConfig": {"path": "./custom-webpack.config.js"},

Notice change in builder and new option customWebpackConfig. Also change

    "serve": {
      "builder": "@angular-builders/dev-server:generic",

Notice the change in builder again for serve target. Post these changes you can create a file called custom-webpack.config.js in your same root directory and add your webpack config there.

However, unlike ng eject configuration provided here will be merged with default config so just add stuff you want to edit/add.

How to display with n decimal places in Matlab

You can convert a number to a string with n decimal places using the SPRINTF command:

>> x = 1.23;
>> sprintf('%0.6f', x)

ans =


>> x = 1.23456789;
>> sprintf('%0.6f', x)

ans =


How to find foreign key dependencies in SQL Server?

If you plan on deleting or renaming a table or column finding only foreign key dependencies might not be enough.

Referencing tables not connected with foreign key - You’ll also need to search for referencing tables that might not be connected with foreign key (I’ve seen many databases with bad design that didn’t have foreign keys defined but that did have related data). Solution might be to search for column name in all tables and look for similar columns.

Other database objects – this is probably a bit off topic but if you were looking for all references than it’s also important to check for dependent objects.

GUI Tools – Try SSMS “Find related objects” option or tools such as ApexSQL Search (free tool, integrates into SSMS) to identify all dependent objects including tables connected with foreign key.

How to loop in excel without VBA or macros?

@Nat gave a good answer. But since there is no way to shorten a code, why not use contatenate to 'generate' the code you need. It works for me when I'm lazy (at typing the whole code in the cell).

So what we need is just identify the pattern > use excel to built the pattern 'structure' > add " = " and paste it in the intended cell.

For example, you want to achieve (i mean, enter in the cell) :

=IF('testsheet'!$C$1 <= 99,'testsheet'!$A$1,"") &IF('testsheet'!$C$2 <= 99,'testsheet'!$A$2,"") &IF('testsheet'!$C$3 <= 99,'testsheet'!$A$3,"") &IF('testsheet'!$C$4 <= 99,'testsheet'!$A$4,"") &IF('testsheet'!$C$5 <= 99,'testsheet'!$A$5,"") &IF('testsheet'!$C$6 <= 99,'testsheet'!$A$6,"") &IF('testsheet'!$C$7 <= 99,'testsheet'!$A$7,"") &IF('testsheet'!$C$8 <= 99,'testsheet'!$A$8,"") &IF('testsheet'!$C$9 <= 99,'testsheet'!$A$9,"") &IF('testsheet'!$C$10 <= 99,'testsheet'!$A$10,"") &IF('testsheet'!$C$11 <= 99,'testsheet'!$A$11,"") &IF('testsheet'!$C$12 <= 99,'testsheet'!$A$12,"") &IF('testsheet'!$C$13 <= 99,'testsheet'!$A$13,"") &IF('testsheet'!$C$14 <= 99,'testsheet'!$A$14,"") &IF('testsheet'!$C$15 <= 99,'testsheet'!$A$15,"") &IF('testsheet'!$C$16 <= 99,'testsheet'!$A$16,"") &IF('testsheet'!$C$17 <= 99,'testsheet'!$A$17,"") &IF('testsheet'!$C$18 <= 99,'testsheet'!$A$18,"") &IF('testsheet'!$C$19 <= 99,'testsheet'!$A$19,"") &IF('testsheet'!$C$20 <= 99,'testsheet'!$A$20,"") &IF('testsheet'!$C$21 <= 99,'testsheet'!$A$21,"") &IF('testsheet'!$C$22 <= 99,'testsheet'!$A$22,"") &IF('testsheet'!$C$23 <= 99,'testsheet'!$A$23,"") &IF('testsheet'!$C$24 <= 99,'testsheet'!$A$24,"") &IF('testsheet'!$C$25 <= 99,'testsheet'!$A$25,"") &IF('testsheet'!$C$26 <= 99,'testsheet'!$A$26,"") &IF('testsheet'!$C$27 <= 99,'testsheet'!$A$27,"") &IF('testsheet'!$C$28 <= 99,'testsheet'!$A$28,"") &IF('testsheet'!$C$29 <= 99,'testsheet'!$A$29,"") &IF('testsheet'!$C$30 <= 99,'testsheet'!$A$30,"") &IF('testsheet'!$C$31 <= 99,'testsheet'!$A$31,"") &IF('testsheet'!$C$32 <= 99,'testsheet'!$A$32,"") &IF('testsheet'!$C$33 <= 99,'testsheet'!$A$33,"") &IF('testsheet'!$C$34 <= 99,'testsheet'!$A$34,"") &IF('testsheet'!$C$35 <= 99,'testsheet'!$A$35,"") &IF('testsheet'!$C$36 <= 99,'testsheet'!$A$36,"") &IF('testsheet'!$C$37 <= 99,'testsheet'!$A$37,"") &IF('testsheet'!$C$38 <= 99,'testsheet'!$A$38,"") &IF('testsheet'!$C$39 <= 99,'testsheet'!$A$39,"") &IF('testsheet'!$C$40 <= 99,'testsheet'!$A$40,"") 

I didn't type it, I just use "&" symbol to combine arranged cell in excel (another file, not the file we are working on).

Notice that :

part1 > IF('testsheet'!$C$

part2 > 1 to 40

part3 > <= 99,'testsheet'!$A$

part4 > 1 to 40

part5 > ,"") &

  • Enter part1 to A1, part3 to C1, part to E1.
  • Enter " = A1 " in A2, " = C1 " in C2, " = E1 " in E2.
  • Enter " = B1+1 " in B2, " = D1+1 " in D2.
  • Enter " =A2&B2&C2&D2&E2 " in G2
  • Enter " =I1&G2 " in I2

Now select A2:I2 , and drag it down. Notice that the number did the increament per row added, and the generated text is combined, cell by cell and line by line.

  • Copy I41 content,
  • paste it somewhere, add " = " in front, remove the extra & and the back.

Result = code as you intended.

I've use excel/OpenOfficeCalc to help me generate code for my projects. Works for me, hope it helps for others. (:

Getting Gradle dependencies in IntelliJ IDEA using Gradle build

In my case,I was getting error while refreshing gradle ('View'->Tool Windows->Gradle) tab and hit "refresh" and getting this error no such property gradleversion for class jetgradleplugin.

Had to install latest intellij compatible with gradle 5+

Create a CSV File for a user in PHP

    // Connect to database
    $result = mysql_query("select id
    from tablename
    where shid=3");
    list($DBshid) = mysql_fetch_row($result);

    Write date to CSV file

    $_file = 'show.csv';
    $_fp = @fopen( $_file, 'wb' );

    $result = mysql_query("select name,compname,job_title,email_add,phone,url from UserTables where id=3");

    while (list( $Username, $Useremail_add, $Userphone, $Userurl) = mysql_fetch_row($result))
        $_csv_data = $Username.','.$Useremail_add.','.$Userphone.','.$Userurl . "\n";
        @fwrite( $_fp, $_csv_data);
    @fclose( $_fp );

When to use static methods

There are some valid reasons to use static methods:

  • Performance: if you want some code to be run, and don't want to instantiate an extra object to do so, shove it into a static method. The JVM also can optimize static methods a lot (I think I've once read James Gosling declaring that you don't need custom instructions in the JVM, since static methods will be just as fast, but couldn't find the source - thus it could be completely false). Yes, it is micro-optimization, and probably unneeded. And we programmers never do unneeded things just because they are cool, right?

  • Practicality: instead of calling new Util().method(arg), call Util.method(arg), or method(arg) with static imports. Easier, shorter.

  • Adding methods: you really wanted the class String to have a removeSpecialChars() instance method, but it's not there (and it shouldn't, since your project's special characters may be different from the other project's), and you can't add it (since Java is somewhat sane), so you create an utility class, and call removeSpecialChars(s) instead of s.removeSpecialChars(). Sweet.

  • Purity: taking some precautions, your static method will be a pure function, that is, the only thing it depends on is its parameters. Data in, data out. This is easier to read and debug, since you don't have inheritance quirks to worry about. You can do it with instance methods too, but the compiler will help you a little more with static methods (by not allowing references to instance attributes, overriding methods, etc.).

You'll also have to create a static method if you want to make a singleton, but... don't. I mean, think twice.

Now, more importantly, why you wouldn't want to create a static method? Basically, polymorphism goes out of the window. You'll not be able to override the method, nor declare it in an interface (pre-Java 8). It takes a lot of flexibility out from your design. Also, if you need state, you'll end up with lots of concurrency bugs and/or bottlenecks if you are not careful.

Accessing Google Spreadsheets with C# using Google Data API

I wrote a simple wrapper around Google's .Net client library, it exposes a simpler database-like interface, with strongly-typed record types. Here's some sample code:

public class Entity {
    public int IntProp { get; set; }
    public string StringProp { get; set; }

var e1 = new Entity { IntProp = 2 };
var e2 = new Entity { StringProp = "hello" };
var client = new DatabaseClient("[email protected]", "password");
const string dbName = "IntegrationTests";
Console.WriteLine("Opening or creating database");
db = client.GetDatabase(dbName) ?? client.CreateDatabase(dbName); // databases are spreadsheets
const string tableName = "IntegrationTests";
Console.WriteLine("Opening or creating table");
table = db.GetTable<Entity>(tableName) ?? db.CreateTable<Entity>(tableName); // tables are worksheets
var r1 = table.Get(1);

There's also a LINQ provider that translates to google's structured query operators:

var q = from r in table.AsQueryable()
        where r.IntProp > -1000 && r.StringProp == "hello"
        orderby r.IntProp
        select r;

Make anchor link go some pixels above where it's linked to

i was facing the similar issue and i resolved by using following code

$(document).on('click', '', function(event) {
        var $anchor = $(this);
        var desiredHeight = $(window).height() - 577;
        $('html, body').stop().animate({
            scrollTop: $($anchor.attr('href')).offset().top - desiredHeight
        }, 1500, 'easeInOutExpo');

Post multipart request with Android SDK

I can recomend Ion library it use 3 dependences and you can find all three jar files at these two sites: (ion and androidasync) (gson)

try {
   Ion.with(this, "")
   .setMultipartParameter("field1", "This is field number 1")
   .setMultipartParameter("field2", "Field 2 is shorter")
        new File(Environment.getExternalStorageDirectory()+"/testfile.jpg"))
   .setCallback(new FutureCallback<String>() {
        public void onCompleted(Exception e, String result) {
   } catch(Exception e) {
     // Do something about exceptions
        System.out.println("exception: " + e);

this will run async and the callback will be executed in the UI thread once a response is received I strongly recomned that you go to the for futher information

How to exclude file only from root folder in Git

Older versions of git require you first define an ignore pattern and immediately (on the next line) define the exclusion. [tested on version 1.9.3 (Apple Git-50)]


Later versions only require the following [tested on version 2.2.1]


Running interactive commands in Paramiko

The full paramiko distribution ships with a lot of good demos.

In the demos subdirectory, and have full interactive TTY examples which would probably be overkill for your situation.

In your example above ssh_stdin acts like a standard Python file object, so ssh_stdin.write should work so long as the channel is still open.

I've never needed to write to stdin, but the docs suggest that a channel is closed as soon as a command exits, so using the standard stdin.write method to send a password up probably won't work. There are lower level paramiko commands on the channel itself that give you more control - see how the SSHClient.exec_command method is implemented for all the gory details.

Why are interface variables static and final by default?

Just tried in Eclipse, the variable in interface is default to be final, so you can't change it. Compared with parent class, the variables are definitely changeable. Why? From my point, variable in class is an attribute which will be inherited by children, and children can change it according to their actual need. On the contrary, interface only define behavior, not attribute. The only reason to put in variables in interface is to use them as consts which related to that interface. Though, this is not a good practice according to following excerpt:

"Placing constants in an interface was a popular technique in the early days of Java, but now many consider it a distasteful use of interfaces, since interfaces should deal with the services provided by an object, not its data. As well, the constants used by a class are typically an implementation detail, but placing them in an interface promotes them to the public API of the class."

I also tried either put static or not makes no difference at all. The code is as below:

public interface Addable {
    static int count = 6;

    public int add(int i);


public class Impl implements Addable {

    public int add(int i) {
        return i+count;

public class Test {

    public static void main(String... args) {
        Impl impl = new Impl();


How to use orderby with 2 fields in linq?

MyList.OrderBy(x => x.StartDate).ThenByDescending(x => x.EndDate);

TypeScript and field initializers


Since writing this answer, better ways have come up. Please see the other answers below that have more votes and a better answer. I cannot remove this answer since it's marked as accepted.

Old answer

There is an issue on the TypeScript codeplex that describes this: Support for object initializers.

As stated, you can already do this by using interfaces in TypeScript instead of classes:

interface Name {
    first: string;
    last: string;
class Person {
    name: Name;
    age: number;

var bob: Person = {
    name: {
        first: "Bob",
        last: "Smith",
    age: 35,

How to see local history changes in Visual Studio Code?

I built an extension called Checkpoints, an alternative to Local History. Checkpoints has support for viewing history for all files (that has checkpoints) in the tree view, not just the currently active file. There are some other minor differences aswell, but overall they are pretty similar.

Where's the DateTime 'Z' format specifier?

This page on MSDN lists standard DateTime format strings, uncluding strings using the 'Z'.

Update: you will need to make sure that the rest of the date string follows the correct pattern as well (you have not supplied an example of what you send it, so it's hard to say whether you did or not). For the UTC format to work it should look like this:

// yyyy'-'MM'-'dd HH':'mm':'ss'Z'
DateTime utcTime = DateTime.Parse("2009-05-07 08:17:25Z");

Reference — What does this symbol mean in PHP?

Null Coalesce operator "??" (Added in PHP 7)

Not the catchiest name for an operator, but PHP 7 brings in the rather handy null coalesce so I thought I'd share an example.

In PHP 5, we already have a ternary operator, which tests a value, and then returns the second element if that returns true and the third if it doesn't:

echo $count ? $count : 10; // outputs 10

There is also a shorthand for that which allows you to skip the second element if it's the same as the first one: echo $count ?: 10; // also outputs 10

In PHP 7 we additionally get the ?? operator which rather than indicating extreme confusion which is how I would usually use two question marks together instead allows us to chain together a string of values. Reading from left to right, the first value which exists and is not null is the value that will be returned.

// $a is not set
$b = 16;

echo $a ?? 2; // outputs 2
echo $a ?? $b ?? 7; // outputs 16

This construct is useful for giving priority to one or more values coming perhaps from user input or existing configuration, and safely falling back on a given default if that configuration is missing. It's kind of a small feature but it's one that I know I'll be using as soon as my applications upgrade to PHP 7.

Width of input type=text element

input width is 10 + 2 times 1 px for border

How to activate "Share" button in android app?

Create a button with an id share and add the following code snippet.

share.setOnClickListener(new View.OnClickListener() {             
    public void onClick(View v) {

        Intent sharingIntent = new Intent(android.content.Intent.ACTION_SEND);
        String shareBody = "Your body here";
        String shareSub = "Your subject here";
        sharingIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, shareSub);
        sharingIntent.putExtra(android.content.Intent.EXTRA_TEXT, shareBody);
        startActivity(Intent.createChooser(sharingIntent, "Share using"));

The above code snippet will open the share chooser on share button click action. However, note...The share code snippet might not output very good results using emulator. For actual results, run the code snippet on android device to get the real results.

When use ResponseEntity<T> and @RestController for Spring RESTful applications

ResponseEntity is meant to represent the entire HTTP response. You can control anything that goes into it: status code, headers, and body.

@ResponseBody is a marker for the HTTP response body and @ResponseStatus declares the status code of the HTTP response.

@ResponseStatus isn't very flexible. It marks the entire method so you have to be sure that your handler method will always behave the same way. And you still can't set the headers. You'd need the HttpServletResponse or a HttpHeaders parameter.

Basically, ResponseEntity lets you do more.

"Char cannot be dereferenced" error

If Character.isLetter(ch) looks a bit wordy/ugly you can use a static import.

import static java.lang.Character.*;

if(isLetter(ch)) {

} else if(isDigit(ch)) {


Tomcat request timeout

With Tomcat 7, you can add the StuckThreadDetectionValve which will enable you to identify threads that are "stuck". You can set-up the valve in the Context element of the applications where you want to do detecting:

<Context ...>
    threshold="60" />

This would write a WARN entry into the tomcat log for any thread that takes longer than 60 seconds, which would enable you to identify the applications and ban them because they are faulty.

Based on the source code you may be able to write your own valve that attempts to stop the thread, however this would have knock on effects on the thread pool and there is no reliable way of stopping a thread in Java without the cooperation of that thread...

Changing the current working directory in Java?

Use FileSystemView

private FileSystemView fileSystemView;
fileSystemView = FileSystemView.getFileSystemView();
currentDirectory = new File(".");
//listing currentDirectory
File[] filesAndDirs = fileSystemView.getFiles(currentDirectory, false);
fileList = new ArrayList<File>();
dirList = new ArrayList<File>();
for (File file : filesAndDirs) {
if (file.isDirectory())
if (!fileSystemView.isFileSystemRoot(currentDirectory))
    dirList.add(0, new File(".."));
currentDirectory = fileSystemView.getParentDirectory(currentDirectory);

Breaking out of a nested loop

factor into a function/method and use early return, or rearrange your loops into a while-clause. goto/exceptions/whatever are certainly not appropriate here.

def do_until_equal():
  foreach a:
    foreach b:
      if a==b: return

Histogram Matplotlib

This might be useful for someone.

Numpy's histogram function returns the edges of each bin, rather than the value of the bin. This makes sense for floating-point numbers, which can lie within an interval, but may not be the desired result when dealing with discrete values or integers (0, 1, 2, etc). In particular, the length of bins returned from np.histogram is not equal to the length of the counts / density.

To get around this, I used np.digitize to quantize the input, and count the fraction of counts for each bin. You could easily edit to get the integer number of counts.

def compute_PMF(data):
    import numpy as np
    from collections import Counter
    _, bins = np.histogram(data, bins='auto', range=(data.min(), data.max()), density=False)
    h = Counter(np.digitize(data,bins) - 1)
    weights = np.asarray(list(h.values())) 
    weights = weights / weights.sum()
    values = np.asarray(list(h.keys()))
    return weights, values




fitting data with numpy

Note that you can use the Polynomial class directly to do the fitting and return a Polynomial instance.

from numpy.polynomial import Polynomial

p =, y, 4)

p uses scaled and shifted x values for numerical stability. If you need the usual form of the coefficients, you will need to follow with

pnormal = p.convert(domain=(-1, 1))

Global and local variables in R

A bit more along the same lines

attrs <- {}

attrs.a <- 1

f <- function(d) {
    attrs.a <- d


will print "1"

attrs <- {}

attrs.a <- 1

f <- function(d) {
   attrs.a <<- d


Will print "20"

How do I check when a UITextField changes?

In case it is not possible to bind the addTarget to your UITextField, I advise you to bind one of them as suggested above, and insert the code for execution at the end of the shouldChangeCharactersIn method.

nameTextField.addTarget(self, action: #selector(RegistrationViewController.textFieldDidChange(_:)), for: .editingChanged)

@objc func textFieldDidChange(_ textField: UITextField) {
    if phoneNumberTextField.text!.count == 17 && nameTextField.text!.count > 0 {
        continueButtonOutlet.backgroundColor = UIColor(.green)
    } else {
        continueButtonOutlet.backgroundColor = .systemGray

And in call in shouldChangeCharactersIn func.

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {

    guard let text = textField.text else {
        return true
    let lastText = (text as NSString).replacingCharacters(in: range, with: string) as String

    if phoneNumberTextField == textField {
        textField.text = lastText.format("+7(NNN)-NNN-NN-NN", oldString: text)
        return false
    return true

Programmatically navigate using React router

The right answer was for me at the time of writing


But you need to add PropTypes to your component

Header.contextTypes = {
  router: PropTypes.object.isRequired
export default Header;

Don't forget to import PropTypes

import PropTypes from 'prop-types';

List of Timezone IDs for use with FindTimeZoneById() in C#?

DateTime dt;
TimeZoneInfo tzf;
tzf = TimeZoneInfo.FindSystemTimeZoneById("TimeZone String");
dt = TimeZoneInfo.ConvertTime(DateTime.Now, tzf);
lbltime.Text = dt.ToString();

Get an OutputStream into a String

Here's what I ended up doing:

Obj.writeToStream(toWrite, os);
try {
    String out = new String(os.toByteArray(), "UTF-8");
} catch (UnsupportedEncondingException e) {
    fail("Caught exception: " + e.getMessage());

Where os is a ByteArrayOutputStream.

Getting a "This application is modifying the autolayout engine from a background thread" error?

You must not change the UI offside the main thread! UIKit is not thread safe, so that above problem and also some other weird problems will arise if you do that. The app can even crash.

So, to do the UIKit operations, you need to define block and let it be executed on the main queue: such as,

NSOperationQueue.mainQueue().addOperationWithBlock {


How to find unused/dead code in java projects

I'm suprised ProGuard hasn't been mentioned here. It's one of the most mature products around.

ProGuard is a free Java class file shrinker, optimizer, obfuscator, and preverifier. It detects and removes unused classes, fields, methods, and attributes. It optimizes bytecode and removes unused instructions. It renames the remaining classes, fields, and methods using short meaningless names. Finally, it preverifies the processed code for Java 6 or for Java Micro Edition.

Some uses of ProGuard are:

  • Creating more compact code, for smaller code archives, faster transfer across networks, faster loading, and smaller memory footprints.
  • Making programs and libraries harder to reverse-engineer.
  • Listing dead code, so it can be removed from the source code.
  • Retargeting and preverifying existing class files for Java 6 or higher, to take full advantage of their faster class loading.

Here example for list dead code:

How to read a CSV file into a .NET Datatable

this is the code i use it but your apps must run with net version 3.5

private void txtRead_Click(object sender, EventArgs e)
           // var filename = @"d:\shiptest.txt";

            openFileDialog1.InitialDirectory = "d:\\";
            openFileDialog1.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*";
            DialogResult result = openFileDialog1.ShowDialog();
            if (result == DialogResult.OK)
                if (openFileDialog1.FileName != "")
                    var reader = ReadAsLines(openFileDialog1.FileName);

                    var data = new DataTable();

                    //this assume the first record is filled with the column names
                    var headers = reader.First().Split(',');
                    foreach (var header in headers)

                    var records = reader.Skip(1);
                    foreach (var record in records)

                    dgList.DataSource = data;

        static IEnumerable<string> ReadAsLines(string filename)
            using (StreamReader reader = new StreamReader(filename))
                while (!reader.EndOfStream)
                    yield return reader.ReadLine();

How to handle change of checkbox using jQuery?

Use :checkbox selector:

$(':checkbox').change(function() {

        // do stuff here. It will fire on any checkbox change



How to set standard encoding in Visual Studio


It is possible with EditorConfig.

EditorConfig helps developers define and maintain consistent coding styles between different editors and IDEs.

This also includes file encoding.

EditorConfig is built-in Visual Studio 2017 by default, and I there were plugins available for versions as old as VS2012. Read more from EditorConfig Visual Studio Plugin page.


You can set up a EditorConfig configuration file high enough in your folder structure to span all your intended repos (up to your drive root should your files be really scattered everywhere) and configure the setting charset:

charset: set to latin1, utf-8, utf-8-bom, utf-16be or utf-16le to control the character set.

You can add filters and exceptions etc on every folder level or by file name/type should you wish for finer control.

Once configured then compatible IDEs should automatically do it's thing to make matching files comform to set rules. Note that Visual Studio does not automatically convert all your files but do its bit when you work with files in IDE (open and save).

What next

While you could have a Visual-studio-wide setup, I strongly suggest to still include an EditorConfig root to your solution version control, so that explicit settings are automatically synced to all team members as well. Your drive root editorconfig file can be the fallback should some project not have their own editorconfig files set up yet.

Run Button is Disabled in Android Studio

I'm using Linux where I had a symlink in my home folder pointing to a folder containing the Android Studio projects. Loading a project using the symlink failed, loading a project from the folder where the symlink is pointing to worked!

How to get a password from a shell script without echoing

A POSIX compliant answer. Notice the use of /bin/sh instead of /bin/bash. (It does work with bash, but it does not require bash.)

stty -echo
printf "Password: "
stty echo
printf "\n"

displayname attribute vs display attribute

They both give you the same results but the key difference I see is that you cannot specify a ResourceType in DisplayName attribute. For an example in MVC 2, you had to subclass the DisplayName attribute to provide resource via localization. Display attribute (new in MVC3 and .NET4) supports ResourceType overload as an "out of the box" property.

How to build minified and uncompressed bundle with webpack?

You can format your webpack.config.js like this:

var debug = process.env.NODE_ENV !== "production";
var webpack = require('webpack');

module.exports = {
    context: __dirname,
    devtool: debug ? "inline-sourcemap" : null,
    entry: "./entry.js",
    output: {
        path: __dirname + "/dist",
        filename: "library.min.js"
    plugins: debug ? [] : [
        new webpack.optimize.DedupePlugin(),
        new webpack.optimize.OccurenceOrderPlugin(),
        new webpack.optimize.UglifyJsPlugin({ mangle: false, sourcemap: false }),

And then to build it unminified run (while in the project's main directory):

$ webpack

To build it minified run:

$ NODE_ENV=production webpack

Notes: Make sure that for the unminified version you change the output file name to library.js and for the minified library.min.js so they do not overwrite each other.

What is the difference between properties and attributes in HTML?

When writing HTML source code, you can define attributes on your HTML elements. Then, once the browser parses your code, a corresponding DOM node will be created. This node is an object, and therefore it has properties.

For instance, this HTML element:

<input type="text" value="Name:">

has 2 attributes (type and value).

Once the browser parses this code, a HTMLInputElement object will be created, and this object will contain dozens of properties like: accept, accessKey, align, alt, attributes, autofocus, baseURI, checked, childElementCount, childNodes, children, classList, className, clientHeight, etc.

For a given DOM node object, properties are the properties of that object, and attributes are the elements of the attributes property of that object.

When a DOM node is created for a given HTML element, many of its properties relate to attributes with the same or similar names, but it's not a one-to-one relationship. For instance, for this HTML element:

<input id="the-input" type="text" value="Name:">

the corresponding DOM node will have id,type, and value properties (among others):

  • The id property is a reflected property for the id attribute: Getting the property reads the attribute value, and setting the property writes the attribute value. id is a pure reflected property, it doesn't modify or limit the value.

  • The type property is a reflected property for the type attribute: Getting the property reads the attribute value, and setting the property writes the attribute value. type isn't a pure reflected property because it's limited to known values (e.g., the valid types of an input). If you had <input type="foo">, then theInput.getAttribute("type") gives you "foo" but theInput.type gives you "text".

  • In contrast, the value property doesn't reflect the value attribute. Instead, it's the current value of the input. When the user manually changes the value of the input box, the value property will reflect this change. So if the user inputs "John" into the input box, then:

    theInput.value // returns "John"


    theInput.getAttribute('value') // returns "Name:"

    The value property reflects the current text-content inside the input box, whereas the value attribute contains the initial text-content of the value attribute from the HTML source code.

    So if you want to know what's currently inside the text-box, read the property. If you, however, want to know what the initial value of the text-box was, read the attribute. Or you can use the defaultValue property, which is a pure reflection of the value attribute:

    theInput.value                 // returns "John"
    theInput.getAttribute('value') // returns "Name:"
    theInput.defaultValue          // returns "Name:"

There are several properties that directly reflect their attribute (rel, id), some are direct reflections with slightly-different names (htmlFor reflects the for attribute, className reflects the class attribute), many that reflect their attribute but with restrictions/modifications (src, href, disabled, multiple), and so on. The spec covers the various kinds of reflection.

Use CASE statement to check if column exists in table - SQL Server

Final answer was a combination of two of the above (I've upvoted both to show my appreciation!):

select case 
   when exists (
      SELECT 1 
      FROM Sys.columns c 
      WHERE c.[object_id] = OBJECT_ID('dbo.Tags') 
         AND = 'ModifiedByUserId'
   then 1 
   else 0 

R cannot be resolved - Android error

Whenever you get

R cannot be resolved

then check for the /res directory and there must be some file that have some error in it and that is preventing the application from being built. For example, it may be a layout file or it may be due to some missing resource is, but you already defined it in the XML file.

If you have any additional, even unused (!) or unreferenced (!) images in a folder like res/drawables-mdpi which do not comply to the file naming conventions (may contain only [a-z0-9_.]), the class might not generate, causing the chain of events all the other posts referred to. Hope it helps!

How to implement the Java comparable interface?

You would need to implement the interface and define the compareTo() method. For a good tutorial go to - Tutorials point link or MyKongLink

Tools for making latex tables in R

The stargazer package is another good option. It supports objects from many commonly used functions and packages (lm, glm, svyreg, survival, pscl, AER), as well as from zelig. In addition to regression tables, it can also output summary statistics for data frames, or directly output the content of data frames.

Html/PHP - Form - Input as array

HTML: Use names as

<input name="levels[level][]">
<input name="levels[build_time][]">


$array = filter_input_array(INPUT_POST);
$newArray = array();
foreach (array_keys($array) as $fieldKey) {
    foreach ($array[$fieldKey] as $key=>$value) {
        $newArray[$key][$fieldKey] = $value;

$newArray will hold data as you want

Array ( 
  [0] => Array ( [level] => 1 [build_time] => 123 ) 
  [1] => Array ( [level] => 2 [build_time] => 456 )

How do I remove repeated elements from ArrayList?

If you don't want duplicates, use a Set instead of a List. To convert a List to a Set you can use the following code:

// list is some List of Strings
Set<String> s = new HashSet<String>(list);

If really necessary you can use the same construction to convert a Set back into a List.

How do I set up access control in SVN?

You can use svn+ssh:, and then it's based on access control to the repository at the given location.

This is how I host a project group repository at my uni, where I can't set up anything else. Just having a directory that the group owns, and running svn-admin (or whatever it was) in there means that I didn't need to do any configuration.

Token based authentication in Web API without any user interface

ASP.Net Web API has Authorization Server build-in already. You can see it inside Startup.cs when you create a new ASP.Net Web Application with Web API template.

OAuthOptions = new OAuthAuthorizationServerOptions
    TokenEndpointPath = new PathString("/Token"),
    Provider = new ApplicationOAuthProvider(PublicClientId),
    AuthorizeEndpointPath = new PathString("/api/Account/ExternalLogin"),
    AccessTokenExpireTimeSpan = TimeSpan.FromDays(14),
    // In production mode set AllowInsecureHttp = false
    AllowInsecureHttp = true

All you have to do is to post URL encoded username and password inside query string.


If you want to know more detail, you can watch User Registration and Login - Angular Front to Back with Web API by Deborah Kurata.

Kill tomcat service running on any port, Windows

1) Go to (Open) Command Prompt (Press Window + R then type cmd Run this).

2) Run following commands

For all listening ports

netstat -aon | find /i "listening"

Apply port filter

netstat -aon |find /i "listening" |find "8080"

Finally with the PID we can run the following command to kill the process

3) Copy PID from result set

taskkill /F /PID

Ex: taskkill /F /PID 189

Sometimes you need to run Command Prompt with Administrator privileges

Done !!! you can start your service now.

How to return a 200 HTTP Status Code from ASP.NET MVC 3 controller

In your controller you'd return an HttpStatusCodeResult like this...

public ActionResult SomeMethod(...your method parameters go here...)
   // todo: put your processing code here

   //If not using MVC5
   return new HttpStatusCodeResult(200);

   //If using MVC5
   return new HttpStatusCodeResult(HttpStatusCode.OK);  // OK = 200

How to use support FileProvider for sharing content to other apps?

If you get an image from camera none of these solutions work for Android 4.4. In this case it's better to check versions.

Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
if (intent.resolveActivity(getContext().getPackageManager()) != null) {
        uri = Uri.fromFile(file);
    } else {
        uri = FileProvider.getUriForFile(getContext(), getContext().getPackageName() + ".provider", file);
    intent.putExtra(MediaStore.EXTRA_OUTPUT, uri);
    startActivityForResult(intent, CAMERA_REQUEST);

How to fix org.hibernate.LazyInitializationException - could not initialize proxy - no Session

This means that the object which you are trying to access is not loaded, so write a query that makes a join fetch of the object which you are trying to access.


If you are trying to get ObjectB from ObjectA where ObjectB is a foreign key in ObjectA.

Query :

SELECT objA FROM ObjectA obj JOIN FETCH obj.objectB objB

how to show calendar on text box click in html

jQuery Mobile has a datepicker too. Source

Just include the following files,

  <script src="jQuery.ui.datepicker.js"></script>
  <script src=""></script>

test if display = none

Try this instead to only select the visible elements under the tbody:

$('tbody :visible').highlight(myArray[i]);

How to get the string size in bytes?

While sizeof works for this specific type of string:

char str[] = "content";
int charcount = sizeof str - 1; // -1 to exclude terminating '\0'

It does not work if str is pointer (sizeof returns size of pointer, usually 4 or 8) or array with specified length (sizeof will return the byte count matching specified length, which for char type are same).

Just use strlen().

ASP.NET Background image

Just a heads up, while some of the answers posted here are correct (in a sense) one thing that you may need to do is go back to the root folder to delve down into the folder holding the image you want to set as the background. In other words, this code is correct in accomplishing your goal:

body {

But you may also need to add a little more to the code, like this:

body {

The difference, as you can see, is that you may need to add “../” in front of the “images/background.png” call. This same rule also applies in HTML5 web pages. So if you are trying the first sample code listed here and you are still not getting the background image, try adding the “../” in front of “images”. Hope this helps .

OpenJDK availability for Windows OS

You can go to AdoptOpenJDK to download your binaries for all platforms provided by a great community.

How can I change or remove HTML5 form validation default error messages?

I found a bug on Mahoor13 answer, it's not working in loop so I've fixed it with this correction:


<input type="email" id="eid" name="email_field" oninput="check(this)">


function check(input) {  
        input.setCustomValidity("Dude '" + input.value + "' is not a valid email. Enter something nice!!");  
    else {  

It will perfectly running in loop.

How to count the NaN values in a column in pandas DataFrame

One other simple option not suggested yet, to just count NaNs, would be adding in the shape to return the number of rows with NaN.


How to select multiple rows filled with constants?

SELECT 1, 2, 3

Are (non-void) self-closing tags valid in HTML5?

However -just for the record- this is invalid:

<address class="vcard">
  <svg viewBox="0 0 800 400">
    <rect width="800" height="400" fill="#000">

And a slash here would make it valid again:

    <rect width="800" height="400" fill="#000"/>

Url.Action parameters?

Here is another simple way to do it

<a class="nav-link"
   href='@Url.Action("Print1", "DeviceCertificates", new { Area = "Diagnostics"})\@Model.ID'>Print</a>

Where is @Model.ID is a parameter

And here there is a second example.

<a class="nav-link"
   href='@Url.Action("Print1", "DeviceCertificates", new { Area = "Diagnostics"})\@Model.ID?param2=ViewBag.P2&param3=ViewBag.P3'>Print</a>

How to show Alert Message like "successfully Inserted" after inserting to DB using MVC3

The 'best' way to do this would be to set a property on a view object once the update is successful. You can then access this property in the view and inform the user accordingly.

Having said that it would be possible to trigger an alert from the controller code by doing something like this -

public ActionResult ActionName(PostBackData postbackdata)
    //your DB code
    return new JavascriptResult { Script = "alert('Successfully registered');" };

You can find further info in this question - How to display "Message box" using MVC3 controller

Select from where field not equal to Mysql Php

The key is the sql query, which you will set up as a string:

$sqlquery = "SELECT field1, field2 FROM table WHERE NOT columnA = 'x' AND NOT columbB = 'y'";

Note that there are a lot of ways to specify NOT. Another one that works just as well is:

$sqlquery = "SELECT field1, field2 FROM table WHERE columnA != 'x' AND columbB != 'y'";

Here is a full example of how to use it:

$link = mysql_connect($dbHost,$dbUser,$dbPass) or die("Unable to connect to database");
mysql_select_db("$dbName") or die("Unable to select database $dbName");
$sqlquery = "SELECT field1, field2 FROM table WHERE NOT columnA = 'x' AND NOT columbB = 'y'";

while ($row = mysql_fetch_assoc($result) {
//do stuff

You can do whatever you would like within the above while loop. Access each field of the table as an element of the $row array which means that $row['field1'] will give you the value for field1 on the current row, and $row['field2'] will give you the value for field2.

Note that if the column(s) could have NULL values, those will not be found using either of the above syntaxes. You will need to add clauses to include NULL values:

$sqlquery = "SELECT field1, field2 FROM table WHERE (NOT columnA = 'x' OR columnA IS NULL) AND (NOT columbB = 'y' OR columnB IS NULL)";

Open a PDF using VBA in Excel

Here is a simplified version of this script to copy a pdf into a XL file.

Sub CopyOnePDFtoExcel()

    Dim ws As Worksheet
    Dim PDF_path As String

    PDF_path = "C:\Users\...\Documents\This-File.pdf"

    'open the pdf file
    ActiveWorkbook.FollowHyperlink PDF_path

    SendKeys "^a", True
    SendKeys "^c"

    Call Shell("TaskKill /F /IM AcroRd32.exe", vbHide)

    Application.ScreenUpdating = False

    Set ws = ThisWorkbook.Sheets("Sheet1")


    Application.ScreenUpdating = True

End Sub