IOS - Dismiss keyboard when UIPickerView is touched - ios

Question

I am building a converter app. In the main screen I have a text field to input numbers and below the text field a picker view will allow users to select conversion parameters, (for example kg to g).
I can hide the keyboard when user click the background by using the following method
(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
[self.enterInput resignFirstResponder];
but when I touch the picker view the keyboard is not hiding.
My question is how to dismiss the keyboard when a user touches the picker view.

Answer 1

Got a solution
1) First Create a hidden roundRect botton and change the type to custom (fit the size of the picker).
2) Create a touch up inside action
- (IBAction)hiddenButtonToHideKeyboard:(id)sender {
[self.enterInput resignFirstResponder];
}
3) Create a keyboard appear notification
[[NSNotificationCenter defaultCenter]addObserver:self selector:#selector(onKeyboardAppear:) name:UIKeyboardWillShowNotification object:nil];
4) Create a keyboard disappear notification
[[NSNotificationCenter defaultCenter]addObserver:self selector:#selector(onKeyboardHide:) name:UIKeyboardWillHideNotification object:nil];
5) Make the button visible when keyboard is appeared
-(void)onKeyboardAppear:(NSNotification *)notification
{
hiddenButtonToHideKeyboard.hidden=NO;
}
6) Hide the button when the keyboard is disappeared
-(void)onKeyboardHide:(NSNotification *)notification
{
hiddenButtonToHideKeyboard.hidden=YES;
}
5) done
I dont think it is a perfect solution but it works for me :)

Answer 2

I use this in my code. I climb the responder chain and reassign the responder. I put this in my method that shows the pickerView. So far no unexpected issues. Seems to work if a keyboard was showing and seems not to crash if there wasn't a keyboard showing.
[[UIApplication sharedApplication] sendAction:#selector(resignFirstResponder) to:nil from:nil forEvent:nil];

Answer 3

Here you go. UIPickerViews are a fairly complex system of nested UIViews which is why you weren't getting any response from the touchesBegan:withEvent: method. What you can do is create your UIPickerView subclass as follows:
//
// MyPickerView.h
//
#import <UIKit/UIKit.h>
// Protocol Definition that extends UIPickerViewDelegate and adds a method to indicate a touch
#protocol MyPickerViewDelegate <UIPickerViewDelegate>
// This is the method we'll call when we've received a touch. Our view controller should implement it and hide the keyboard
- (void)pickerViewDidReceiveTouch:(UIPickerView *)pickerView;
#end
#interface MyPickerView : UIPickerView
// We're redefining delegate to require conformity to the MyPickerViewDelegate protocol we just made
#property (nonatomic, weak) id <MyPickerViewDelegate>delegate;
#end
//
// MyPickerView.m
//
#import "MyPickerView.h"
#implementation MyPickerView
#synthesize delegate = _myPickerViewDelegate; // We changed the data type of delegate as it was declared in the superclass so it's important to link it to a differently named backing variable
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
// We make sure to call the super method so all standard functionality is preserved
UIView *hitView = [super hitTest:point withEvent:event];
if (hitView) {
// This will be true if the hit was inside of the picker
[_myPickerViewDelegate pickerViewDidReceiveTouch:self];
}
// Return our results, again as part of preserving our superclass functionality
return hitView;
}
#end
Then in your ViewController change it to conform to <MyPickerViewDelegate> instead of <UIPickerViewDelegate>. This is ok since MyPickerViewDelegate inherits from UIPickerViewDelegate and will pass through the standard UIPickerViewDelegate methods.
Finally implement pickerViewDidReceiveTouch: in your view controller:
- (void)pickerViewDidReceiveTouch:(UIPickerView *)pickerView {
[enterInput resignFirstResponder];
}