[ios] Color Tint UIButton Image

I noticed that when I place a white or black UIImage into a UISegmentedControl it automatically color masks it to match the tint of the segmented control. I thought this was really cool, and was wondering if I could do this elsewhere as well. For example, I have a bunch of buttons that have a uniform shape but varied colors. Instead of making a PNG for each button, could I somehow use this color masking to use the same image for all of them but then set a tint color or something to change their actual color?

For Xamarin.iOS (C#):

UIButton messagesButton = new UIButton(UIButtonType.Custom);
UIImage icon = UIImage.FromBundle("Images/icon.png");
messagesButton.SetImage(icon.ImageWithRenderingMode(UIImageRenderingMode.AlwaysTemplate), UIControlState.Normal);
messagesButton.TintColor = UIColor.White;
messagesButton.Frame = new RectangleF(0, 0, 25, 25);

To set white colour of the image(arrow icon) on the button, we're using:

let imageOnButton = UIImage(named: "navForwardArrow")?.imageWithColor(color: UIColor.white)
button.setImage(imageOnButton, for: .normal)

Known issue: The icon looses its white colour while the button is pressed.

Screenshot:

None of above worked for me, because tint was cleared after click. I had to use

button.setImageTintColor(Palette.darkGray(), for: UIControlState())

As Ric already mentioned in his post you can set the render mode in code, you can also do this directly in the image catalog, see attached image below. Just set the Render As to Template Image

Caveat I have had problems with iOS 7 and this approach. So if you use iOS 7 as well you might want to do it in code as well to be sure, as described here.

Swift 4 with customType:

let button = UIButton(frame: aRectHere)
    let buttonImage = UIImage(named: "imageName")
    button.setImage(buttonImage?.withRenderingMode(.alwaysTemplate), for: .normal)
    button.tintColor = .white

Change button image or image view tint color Swift :

btn.imageView?.image = btn.imageView?.image?.withRenderingMode(.alwaysTemplate)

btn.imageView?.tintColor = #colorLiteral(red: 0, green: 0, blue: 0, alpha: 1)

Custom Buttons appear in their respective image colors. Setting the button type to "System" in the storyboard (or to UIButtonTypeSystem in code), will render the button's image with the default tint color.

(tested on iOS9, Xcode 7.3)

Swift 3.0

    let image = UIImage(named:"NoConnection")!

 warningButton = UIButton(type: .system)        
    warningButton.setImage(image, for: .normal)
    warningButton.tintColor = UIColor.lightText
    warningButton.frame = CGRect(origin: CGPoint(x:-100,y:0), size: CGSize(width: 59, height: 56))

    self.addSubview(warningButton)

If you want to manually mask your image, here is updated code that works with retina screens

- (UIImage *)maskWithColor:(UIColor *)color
{
    CGImageRef maskImage = self.CGImage;
    CGFloat width = self.size.width * self.scale;
    CGFloat height = self.size.height * self.scale;
    CGRect bounds = CGRectMake(0,0,width,height);

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef bitmapContext = CGBitmapContextCreate(NULL, width, height, 8, 0, colorSpace, kCGBitmapAlphaInfoMask & kCGImageAlphaPremultipliedLast);
    CGContextClipToMask(bitmapContext, bounds, maskImage);
    CGContextSetFillColorWithColor(bitmapContext, color.CGColor);
    CGContextFillRect(bitmapContext, bounds);

    CGImageRef cImage = CGBitmapContextCreateImage(bitmapContext);
    UIImage *coloredImage = [UIImage imageWithCGImage:cImage scale:self.scale orientation:self.imageOrientation];

    CGContextRelease(bitmapContext);
    CGColorSpaceRelease(colorSpace);
    CGImageRelease(cImage);

    return coloredImage;
}

You must set the image rendering mode to UIImageRenderingModeAlwaysTemplate in order to have the tintColor affect the UIImage. Here is the solution in Swift:

let image = UIImage(named: "image-name")
let button = UIButton()
button.setImage(image?.imageWithRenderingMode(UIImageRenderingMode.AlwaysTemplate), forState: .Normal)
button.tintColor = UIColor.whiteColor()

SWIFT 4x

button.setImage(image.withRenderingMode(UIImage.RenderingMode.alwaysTemplate), for: .normal)
button.tintColor = UIColor.blue

If you have a custom button with a background image.You can set the tint color of your button and override the image with following .

In assets select the button background you want to set tint color.

In the attribute inspector of the image set the value render as to "Template Image"

Now whenever you setbutton.tintColor = UIColor.red you button will be shown in red.

Not sure exactly what you want but this category method will mask a UIImage with a specified color so you can have a single image and change its color to whatever you want.

ImageUtils.h

- (UIImage *) maskWithColor:(UIColor *)color;

ImageUtils.m

-(UIImage *) maskWithColor:(UIColor *)color 
{
    CGImageRef maskImage = self.CGImage;
    CGFloat width = self.size.width;
    CGFloat height = self.size.height;
    CGRect bounds = CGRectMake(0,0,width,height);

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef bitmapContext = CGBitmapContextCreate(NULL, width, height, 8, 0, colorSpace, kCGImageAlphaPremultipliedLast);
    CGContextClipToMask(bitmapContext, bounds, maskImage);
    CGContextSetFillColorWithColor(bitmapContext, color.CGColor);    
    CGContextFillRect(bitmapContext, bounds);

    CGImageRef cImage = CGBitmapContextCreateImage(bitmapContext);
    UIImage *coloredImage = [UIImage imageWithCGImage:cImage];

    CGContextRelease(bitmapContext);
    CGColorSpaceRelease(colorSpace);
    CGImageRelease(cImage);

    return coloredImage;    
}

Import the ImageUtils category and do something like this...

#import "ImageUtils.h"

...

UIImage *icon = [UIImage imageNamed:ICON_IMAGE];

UIImage *redIcon = [icon maskWithColor:UIColor.redColor];
UIImage *blueIcon = [icon maskWithColor:UIColor.blueColor];

Swift 3:

This solution could be comfortable if you have already setted your image through xCode interface builder. Basically you have one extension to colorize an image:

extension UIImage {
    public func image(withTintColor color: UIColor) -> UIImage{
        UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)
        let context: CGContext = UIGraphicsGetCurrentContext()!
        context.translateBy(x: 0, y: self.size.height)
        context.scaleBy(x: 1.0, y: -1.0)
        context.setBlendMode(CGBlendMode.normal)
        let rect: CGRect = CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height)
        context.clip(to: rect, mask: self.cgImage!)
        color.setFill()
        context.fill(rect)
        let newImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()
        return newImage
    }
}

Then , you can prepare this UIButton extension to colorize the image for a particular state:

extension UIButton {
    func imageWith(color:UIColor, for: UIControlState) {
        if let imageForState = self.image(for: state) {
            self.image(for: .normal)?.withRenderingMode(.alwaysTemplate)
            let colorizedImage = imageForState.image(withTintColor: color)
            self.setImage(colorizedImage, for: state)
        }
    }
}

Usage:

myButton.imageWith(.red, for: .normal)

P.S. (working good also in table cells, you don't need to call setNeedDisplay() method, the change of the color is immediate due to the UIImage extension..

You Should Try

After Setting The Frame

NSArray *arr10 =[NSArray arrayWithObjects:btn1,btn2,nil];
for(UIButton *btn10 in arr10)
{
CAGradientLayer *btnGradient2 = [CAGradientLayer layer];
btnGradient2.frame = btn10.bounds;

btnGradient2.colors = [NSArray arrayWithObjects:
                       (id)[[UIColor colorWithRed:151.0/255.0f green:206.0/255.5 blue:99.0/255.0 alpha:1] CGColor],
                       (id)[[UIColor colorWithRed:126.0/255.0f green:192.0/255.5 blue:65.0/255.0 alpha:1]CGColor],
                       nil];
[btn10.layer insertSublayer:btnGradient2 atIndex:0];

}

In Swift you can do that like so:

var exampleImage = UIImage(named: "ExampleImage.png")?.imageWithRenderingMode(.AlwaysTemplate)

Then in your viewDidLoad

exampleButtonOutlet.setImage(exampleImage, forState: UIControlState.Normal)

And to modify the color

exampleButtonOutlet.tintColor = UIColor(red: 1, green: 0, blue: 0, alpha: 1) //your color

EDIT Xcode 8 Now you can also just the rendering mode of the image in your .xcassets to Template Image and then you don't need to specifically declare it in the var exampleImage anymore