LK. LK. - 5 months ago 16
Objective-C Question

Find which child view was tapped when using UITapGestureRecognizer

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

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?`
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