Question

I have button created programmatically in the UIImageView. This view was also created programmatically. When image in this view is tapped the button is created, now I want to capture when this button is tapped but I’m unable to here is my relevant code :

- (void)imageTapped:(UIGestureRecognizer *)sender{ 
    MyImageView *myView = (MyImageView *)sender.view;
    NSLog(@"Image tapped is => %@", myView.currentImageName); 

    //add button to view
    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    [button addTarget:self 
               action:@selector(pressedPlay:)
     forControlEvents:UIControlEventTouchDown];

    //button image
    UIImage *backgroundImage = [UIImage imageNamed:[NSString stringWithFormat:@"playbutton.png"]];

    button.frame = CGRectMake(85.0, 175.0, backgroundImage.size.width, backgroundImage.size.height);

    myView.userInteractionEnabled = YES;
    button.userInteractionEnabled = YES;

    [button setImage:backgroundImage forState:(UIControlStateNormal)];
    [myView addSubview:button];
}

Now this code should handle the tap but for some reason it doesn’t :

- (void)pressedPlay:(UIGestureRecognizer *)sender{ 
    //MyImageView *senderView = (MyImageView *) sender.view;
    NSLog(@"%@", @"I Presed button");    
}

Any reason why this is not working?

Answer 1

Your code suggests that you are using a UIGestureRecognizer (most likely a UITapGestureRecognizer) to detect the initial tap. The problem is that UIGestureRecognizer is being greedy and stopping the UIButton from receiving the touch.

You will need to do some shifting to disable the gesture recognizer after the initial detection and then reenable it after the play has been tapped.

UIGestureRecognizer has the property

@property(nonatomic, getter=isEnabled) BOOL enabled

or you can choose to implement UIGestureRecognizerDelegate and provide an implementation of

gestureRecognizer:shouldReceiveTouch:

a very simple attempt could look like:

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch;
{
    return ![touch.view isKindOfClass:[UIButton class]];
}

and don’t forget to set the delegate on the gesture recognizer

myGesture.delegate = self;