如何为 UIViewController.view 中也具有 UITapGestureRecognizer 的 UIView 挑选和操作 UITapGestureRecognizer？

Posted 2023-02-23

【中文标题】如何为 UIViewController.view 中也具有 UITapGestureRecognizer 的 UIView 挑选和操作 UITapGestureRecognizer？

【英文标题】：How to single out and action a UITapGestureRecognizer for a UIView that is in the UIViewController.view that also has a UITapGestureRecognizer?

【发布时间】：2020-06-10 10:12:58

【问题描述】：

我有一个 UIView 对象，我添加了一个 UITapGestureRecognizer。主视图还有一个我用来隐藏键盘的 UITapGestureRecognizer。我如何优先考虑子 UIView 上的 tapGesture 来做我需要做的事情？我希望在点击子视图时触发与此点击相关的操作，而不是主视图的手势。

我尝试向子视图添加双击，以区分这两种手势，但这只会触发主视图的点击动作。

var childView: UIView!

 /**Tap screen event listener - to hide the keyboard*/
 let tapGesture = UITapGestureRecognizer.init(target: self, action: #selector(hideKeyBaord))
 self.view.addGestureRecognizer(tapGesture)


 let doubleTap = UITapGestureRecognizer.init(target: self, action: #selector(doSomethingElse))
 doubleTap.numberOfTouchesRequired = 2
 childView.view.addGestureRecognizer(doubleTap)

【问题讨论】：

“优先”是什么意思？您的意思是如果子视图的手势识别器激活，您不希望主视图的手势识别器激活？

@Sweeper 是的，请

【参考方案1】：

一种方法是为tapGesture 实现shouldReceiveTouch 委托方法：

extension YourViewController : UIGestureRecognizerDelegate 
    override func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldReceive touch: UITouch) -> Bool 
        if gestureRecogniser == tapGesture 
            // tapGesture should not receive the touch when the touch is inside the child view
            let location = touch.location(in: childView)
            return !childView.bounds.contains(location)
         else 
            return true
        
    

记得将tapGesture 的委托设置为self。