如何确定UITapGestureRecognizer触摸了哪个视图？

Question

I have a UIScrollView with subviews and a UITapGestureRecognizer .

I create the recognizer like this:

UITapGestureRecognizer *tgr = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapGestureRecognized:)];
[self addGestureRecognizer:tgr];

The view property of UITapGestureRecognizer points to the scroll view itself even if the user touched a different view. I need to know if touch went down on the scroll view directly.

Answer 1

Paul's suggestions are good, but if you don't want (or can't) subclass or become the delegate of the recognizer, there's another way.

You can ask the gesture recognizer for its locationInView: and then retrieve the view which that point is on top of with your scrollView's hitTest:withEvent: method (defined on UIView). Something like:

CGPoint location = [recognizer locationInView:scrollView];
UIView *touchedView = [scrollView hitTest:location withEvent:nil];

Answer 2

You can become either subclass UITapGestureRecognizer and add a new ivar to hold this info by overriding the touchesBegan:withEvent: method something like this

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
  /*
   * If you wanted you could store a set of all the views to allow
   * for multiple touches
   */
  self.touchedView = [touches.anyObject view];
  [super touchesBegan:touches withEvent:event];
}

Or if you like you can become the delegate for UITapGestureRecognizer and store the tapped view as a property in your class by implementing gestureRecognizer:shouldReceiveTouch: