How to set a default Value of a UIPickerView

Question

I have a problem with my UIPickerView  I have 3 values in it EU AP and NA  When I start the app EU seems to be selected but when I make a NSLog         regions objectAtIndex row    I only get back  null   now when I touch the UIPickerView the EU value is selected and I get  EU  back from a NSLog   My question is    How can I define a default value which is selected  not only the label  when the user only starts the app and touches nothing   Edit  Here is my code to get the selected item    pragma mark -  pragma mark PickerView DataSource  -  NSInteger numberOfComponentsInPickerView   UIPickerView   pickerView       return 1    -  NSInteger pickerView  UIPickerView   pickerView numberOfRowsInComponent  NSInteger component       return  regions count     -  NSString   pickerView  UIPickerView   pickerView              titleForRow  NSInteger row             forComponent  NSInteger component       return  regions objectAtIndex row       pragma mark -  pragma mark PickerView Delegate - void pickerView  UIPickerView   pickerView didSelectRow  NSInteger row       inComponent  NSInteger component                    selectedRegion     NSString alloc  initWithFormat                                        regions objectAtIndex row        NSLog        selectedRegion

User · Answer

For example  you populated your UIPickerView with array values  then you wanted    to select a certain array value in the first load of pickerView like  Arizona   Note that the word  Arizona  is at index 2  This how to do it    Enjoy coding   NSArray  countryArray   NSArray arrayWithObjects   Alabama    Alaska    Arizona    Arkansas   nil   UIPickerView  countryPicker   UIPickerView alloc initWithFrame self view bounds   countryPicker delegate self  countryPicker dataSource self   countryPicker selectRow 2 inComponent 0 animated YES    self view addSubview countryPicker

User · Answer

I too had this problem   But apparently there is an issue of the order of method calls   You must call    self picker selectRow 2 inComponent 0 animated YES     after calling   self view addSubview self picker

User · Answer

Swift solution   Define an Outlet    IBOutlet weak var pickerView  UIPickerView      for example   Then in your viewWillAppear or your viewDidLoad  for example  you can use the following   pickerView selectRow rowMin  inComponent  0  animated  true  pickerView selectRow rowSec  inComponent  1  animated  true    If you inspect the Swift 2 0 framework you ll see  selectRow defined as   func selectRow row  Int  inComponent component  Int  animated  Bool     option clicking  selectRow in Xcode displays the following

User · Answer

In normal case  you can do something like this in viewDidLoad method        picker selectRow 1 inComponent 0 animated YES     In my case  I d like to fetch data from api server and display them onto UIPickerView then I want the picker to select the first item by default   The UIPickerView will look like it selected the first item after it was created  but when you try to get the selected index by using selectedRowInComponent  you will get NSNull  That s because it detected nothing changed by the user  select 0 from 0     Following is my solution  in viewWillAppear  after I fetched the data     picker selectRow 1 inComponent 0 animated NO     picker selectRow 0 inComponent 0 animated NO     Its a bit dirty  but dont worry  the UI rendering in iOS is very fast

User · Answer

TL DR version     Objective-C  self picker selectRow 2 inComponent 0 animated YES     Swift picker selectRow 2  inComponent 0  animated true      Either you didn t set your picker to select the row  which you say you seem to have done but anyhow    -  void selectRow  NSInteger row inComponent  NSInteger component animated  BOOL animated   OR you didn t use the the following method to get the selected item from your picker  -  NSInteger selectedRowInComponent  NSInteger component   This will get the selected row as Integer from your picker and do as you please with it  This should do the trick for yah  Good luck   Anyhow read the ref  https   developer apple com documentation uikit uipickerview    EDIT   An example of manually setting and getting of a selected row in a UIPickerView   the  h file    import  lt UIKit UIKit h gt    interface ViewController   UIViewController  lt UIPickerViewDelegate  UIPickerViewDataSource gt        UIPickerView  picker      NSMutableArray  source      property  nonatomic retain  UIPickerView  picker   property  nonatomic retain  NSMutableArray  source   - void pressed    end   the  m file    import  ViewController h    interface ViewController      end  implementation ViewController   synthesize picker   synthesize source   -  void viewDidLoad        super viewDidLoad          Do any additional setup after loading the view  typically from a nib     -  void viewDidUnload        super viewDidUnload          Release any retained subviews of the main view     -  BOOL shouldAutorotateToInterfaceOrientation  UIInterfaceOrientation interfaceOrientation       return YES     -  void  viewWillAppear  BOOL animated        super viewWillAppear animated        self view backgroundColor    UIColor yellowColor        self source     NSMutableArray alloc  initWithObjects   EU     USA     ASIA   nil        UIButton  pressme     UIButton alloc  initWithFrame CGRectMake 20  20  280  80         pressme setTitle   Press me     forState UIControlStateNormal       pressme backgroundColor    UIColor lightGrayColor        pressme addTarget self action  selector pressed  forControlEvents UIControlEventTouchUpInside        self view addSubview pressme        self picker     UIPickerView alloc  initWithFrame CGRectMake 20  110  280  300        self picker delegate   self      self picker dataSource   self       self view addSubview self picker          This is how you manually SET     a selection       self picker selectRow 2 inComponent 0 animated YES        logs the current selection of the picker manually - void pressed         This is how you manually GET     a selection     int row    self picker selectedRowInComponent 0        NSLog         source objectAtIndex row       -  NSInteger numberOfComponentsInPickerView   UIPickerView   pickerView       return 1     -  NSInteger pickerView  UIPickerView   pickerView numberOfRowsInComponent  NSInteger component       return  source count      -  NSString   pickerView  UIPickerView   pickerView              titleForRow  NSInteger row             forComponent  NSInteger component       return  source objectAtIndex row       pragma mark -  pragma mark PickerView Delegate - void pickerView  UIPickerView   pickerView didSelectRow  NSInteger row       inComponent  NSInteger component         NSLog         source objectAtIndex row        end     EDIT for Swift solution  Source  Dan Beaulieu s answer   Define an Outlet    IBOutlet weak var pickerView  UIPickerView      for example   Then in your viewWillAppear or your viewDidLoad  for example  you can use the following   pickerView selectRow rowMin  inComponent  0  animated  true  pickerView selectRow rowSec  inComponent  1  animated  true    If you inspect the Swift 2 0 framework you ll see  selectRow defined as   func selectRow row  Int  inComponent component  Int  animated  Bool     option clicking  selectRow in Xcode displays the following

User · Answer

You have to  send  -  void selectRow  NSInteger row inComponent  NSInteger component animated  BOOL animated to the picker view before it appears  The documentation states that the method selectedRowInComp    will give -1  thus it is possible that the picker view is in a state with no selected row  It turns out to be in that state when created

User · Answer

This is How to set a default Value of a UIPickerView   self picker selectRow 4 inComponent 0 animated YES

[ios] How to set a default Value of a UIPickerView

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