Gesture recognizer and button actions

问题

I have a view hierarchy that looks something like this:

UIView (A)
UIView > UIImageView
UIView > UIView (B)
UIView > UIView (B) > Rounded Rect Button
UIView > UIView (B) > UIImageView
UIView > UIView (B) > UILabel

I\'ve attached gesture recognizer(s) to my UIView (B). The problem that i\'m facing is that i don\'t get any actions for the Rounded Rect Button which is inside the UIView (B). The singleTap gesture recognizer captures/overrides the button\'s Touch Up Inside event.

How can i make it work? I thought that the responder chain hierarchy will make sure that the button touch event will be given preference, and it WILL get triggered! What am i missing?

Here\'s some related code:

#pragma mark -
#pragma mark View lifecycle (Gesture recognizer setup)

- (void)viewDidLoad {
    [super viewDidLoad];

    // double tap gesture recognizer
    UITapGestureRecognizer *dtapGestureRecognize = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(doubleTapGestureRecognizer:)];
    dtapGestureRecognize.delegate = self;
    dtapGestureRecognize.numberOfTapsRequired = 2;
    [self.viewB addGestureRecognizer:dtapGestureRecognize];

    // single tap gesture recognizer
    UITapGestureRecognizer *tapGestureRecognize = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(singleTapGestureRecognizer:)];
    tapGestureRecognize.delegate = self;
    tapGestureRecognize.numberOfTapsRequired = 1;
    [tapGestureRecognize requireGestureRecognizerToFail:dtapGestureRecognize];
    [self.viewB addGestureRecognizer:tapGestureRecognize];

    // add gesture recodgnizer to the grid view to start the edit mode
    UILongPressGestureRecognizer *pahGestureRecognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressGestureRecognizerStateChanged:)];
    pahGestureRecognizer.delegate = self;
    pahGestureRecognizer.minimumPressDuration = 0.5;
    [self.viewB addGestureRecognizer:pahGestureRecognizer];

    [dtapGestureRecognize release];
    [tapGestureRecognize release];
    [pahGestureRecognizer release];
}

#pragma mark -
#pragma mark Button actions

- (IBAction)buttonTouchUpInside:(id)sender {
    NSLog(@\"%s, %@\", __FUNCTION__, sender);
}

#pragma mark -
#pragma mark Gesture recognizer actions


- (void)singleTapGestureRecognizer:(UIGestureRecognizer *)gestureRecognizer {
    NSLog(@\"%s\", __FUNCTION__);
}

- (void)doubleTapGestureRecognizer:(UIGestureRecognizer *)gestureRecognizer {
    NSLog(@\"%s\", __FUNCTION__);
}

- (void)longPressGestureRecognizerStateChanged:(UIGestureRecognizer *)gestureRecognizer {

    switch (gestureRecognizer.state) {

        case UIGestureRecognizerStateEnded: {
            NSLog(@\"%s\", __FUNCTION__);

            break;
        }
        default:
            break;
    }
}

回答1:

In the "shouldReceiveTouch" method you should add a condition that will return NO if the touch is in the button.

This is from apple SimpleGestureRecognizers example.

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {

    // Disallow recognition of tap gestures in the segmented control.
    if ((touch.view == yourButton)) {//change it to your condition
        return NO;
    }
    return YES;
}

hope it will help

Edit

As Daniel noted you must conform to UIGestureRecognizerDelegate for it to work.

shani

回答2:

I also had the same problem , then i tried with

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch{

    if ([touch.view isKindOfClass:[UIButton class]]) {      //change it to your condition
        return NO;
    }
    return YES;
}

It is working now perfectly.........

回答3:

Generally speaking, we use below delegate method to avoid the touch in all kinds of UIControls:

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
    if (([touch.view isKindOfClass:[UIControl class]])) {
         return NO;
    }
    return YES;
}

Note: DO NOT do this check (check the recognizer.view class type) the gestureRecognizerShouldBegin, it won't work.

回答4:

Here is a Swift 3.0 version:

extension UIViewController: UIGestureRecognizerDelegate {

public func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldReceive touch: UITouch) -> Bool {
    if touch.view is UIButton {
        return false
    }
    return true
}

Don't forget to:

Make your tapper object delegate to self (e.g: tapper.delegate = self)

回答5:

Here is a Swift version:

func gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldReceiveTouch touch: UITouch) -> Bool {
    if (touch.view!.isKindOfClass(UIButton)) {
        return false
    }
    return true
}

Don't forget to:

1. Make you class conform to UIGestureRecognizerDelegate
2. Make your tapper object delegate to self (e.g: tapper.delegate = self)

回答6:

The best solution is to my mind using code snippet below:

-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
    CGPoint touchLocation = [touch locationInView:self.view];
    return !CGRectContainsPoint(self.menuButton.frame, touchLocation);
}

来源：https://stackoverflow.com/questions/4825199/gesture-recognizer-and-button-actions