在iOS 7中操作手势识别器

Question

I have a gesture recognizer that I've made on a calculator. It's connected to an action that is activated upon a user's double tap. I connected the gesture recognizer to the main view of the view controller, however the gesture recognizer is also applied to my buttons. So if the user quickly types 11, they'll press 1 two times fast and accidentally activate a function that they don't want to. How do I make it so that the UIGestureRecognizer doesn't act upon buttons? I want to keep the double-tap gesture. I don't want to change it to a two finger tap or something odd like that. However, if there's no other way (which I doubt there is), I could do that.

Answer 1

Try this:

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

    if ((touch.view == yourButton)) {
        return NO;
    }

    return YES;
}

This will be called every time the gesture is recognized, and it will ignore the gesture is the view is your button.

Answer 2

You should adopt UIGestureRegconizerDelegate protocol in your ViewController.h

@interface ViewController : UIViewController <UIGestureRecognizerDelegate>

@end

in your ViewController.m, implement this method

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

and yourGestureRecognizer.delegate = self //your view controller.

Answer 3

Building on Antonio's answer, you could give all of your tag s to make this easier. Presumably, your calculator has more than just one yourButton . Suppose all your buttons have a tag larger than 100:

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

    if ((touch.view.tag > 100)) {
        return NO;
    }
    return YES;
}

This is cleaner than checking the class of the view . You could now have controls where you allow the gesture to be recognised anyway.