objective-c - 查找使用 UITapGestureRecognizer 时点击了哪个 subview

Question

在使用 UIGestureRecognizers 时，我如何知道在哪个 subview 上发生了事件？

根据文档:

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

据我所知，'view' 属性是

The view the gesture recognizer is attached to.

这将是父 View 。

Answer 1

这将在事件的位置找到最里面的后代 View 。 (请注意，如果该 subview 有任何交互式内部私有(private)孙子，则此代码也会找到这些。)

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

在 Swift 2 中:

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

在 Swift 3 中:

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