objective c - Find which child view was tapped when using UITapGestureRecognizer

Question

How do I know on which of the the child views an event occurred when using UIGestureRecognizers?

According to the documentation:

A gesture recognizer operates on touches hit-tested to a specific view and all of that view’s subviews.

As far as I can see, the 'view' property is

The view the gesture recognizer is attached to.

which will be the parent view.

Answer 1

This will find the innermost descendant view at the event's location. (Note that if that child view has any interactive internal private grandchildren this code will find those too.)

UIView* view = gestureRecognizer.view;
CGPoint loc = [gestureRecognizer locationInView:view];
UIView* subview = [view hitTest:loc withEvent:nil];

In Swift 2:

let view = gestureRecognizer.view
let loc = gestureRecognizer.locationInView(view)
let subview = view?.hitTest(loc, withEvent: nil) // note: it is a `UIView?`

In Swift 3:

let view = gestureRecognizer.view
let loc = gestureRecognizer.location(in: view)
let subview = view?.hitTest(loc, with: nil) // note: it is a `UIView?`