Question

我有UIView个子视图，我们称之为A：

基本UIView，名为B
UIScrollView，名为C

我在视图A中覆盖了以下方法：

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event

当我触摸视图B时，touchesBegan:withEvent:和touchesEnded:withEvent:会被调用，但如果我触摸UIScrollView（查看C），则不会调用

我知道这是预期的行为，但我想了解原因。我找不到任何明确的答案。有什么想法吗？

Answer 1

使用TapGestureRecognizer而不是touchBegan方法

UITapGestureRecognizer *singleTapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(singleTap:)];
singleTapGestureRecognizer.numberOfTapsRequired = 1;
singleTapGestureRecognizer.enabled = YES;
singleTapGestureRecognizer.cancelsTouchesInView = NO;
[scrollView addGestureRecognizer:singleTapGestureRecognizer];

- (void)singleTap:(UITapGestureRecognizer *)gesture {  
//handle taps   
}

Swift版本：

let singleTapGestureRecognizer = UITapGestureRecognizer(target: self, action: "singleTap:")
    singleTapGestureRecognizer.numberOfTapsRequired = 1
    singleTapGestureRecognizer.enabled = true
    singleTapGestureRecognizer.cancelsTouchesInView = false
    scrollViewH.addGestureRecognizer(singleTapGestureRecognizer)

func singleTap(sender: UITapGestureRecognizer) {
    println("handle taps ")

}

Answer 2

如果你有滚动视图thouchesBegan方法将无法工作，因为如果想要滚动你必须在storyboard中启用userInteractionEnabled为YES。如果你把它变为NO，它就会触发。所以解决方案是使用TapGestureRecognizer 将其添加到viewDidLoad：

let singleTapGestureRecognizer = UITapGestureRecognizer(target: self, action: "MyTapMethod:")
    singleTapGestureRecognizer.numberOfTapsRequired = 1
    singleTapGestureRecognizer.enabled = true
    singleTapGestureRecognizer.cancelsTouchesInView = false
    myscrollView.addGestureRecognizer(singleTapGestureRecognizer)

然后在控制器中添加此MyTapMethod。

func MyTapMethod(sender: UITapGestureRecognizer) {
        //NSLog("touchesBegan")
        self.view.endEditing(true)
    }

这很好。

Answer 3

您至少有两个选项：

1）“通过为您的滚动视图设置userInteractionEnabled到NO”。更多信息https://stackoverflow.com/a/25108078/1702413

2）将您的UIScrollView子类化 - 例如使用此https://dl.dropboxusercontent.com/u/19438780/ClassScrollViewDelegate.zip

<强>更新

为什么呢？请再次阅读文档：

“因为滚动..它必须知道触摸是否表示意图滚动...它暂时拦截了一个降落事件...... 滚动视图取消子视图中的任何跟踪并执行滚动自己“

最重要的是： **

子类可以覆盖 touchesShouldBegin：withEvent：inContentView：，pagingEnabled，和 touchesShouldCancelInContentView：方法

从这里开始：https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIScrollView_Class/index.html#//apple_ref/doc/uid/TP40006922

Answer 4

Swift 3/4 版本：

let singleTapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(MyViewController.tapRecognized))
singleTapGestureRecognizer.numberOfTapsRequired = 1
singleTapGestureRecognizer.isEnabled = true
singleTapGestureRecognizer.cancelsTouchesInView = false
scrollView.addGestureRecognizer(singleTapGestureRecognizer)

然后：

@objc func tapRecognized() {
    view.endEditing(true)
}

Answer 5

请选中此项以使用滚动视图的平移手势识别触摸事件（开始，移动，结束）

Class CustomScrollView:UIScrollView
{

CustomScrollView()
{

 (this.GestureRecognizers[1] as UIPanGestureRecognizer).AddTarget(() => this.PanHandle(this.GestureRecognizers[1] as UIPanGestureRecognizer));     

}


 private void PanHandle(UIPanGestureRecognizer gestureRecognizer)           
  {
  var touchLocation=gestureRecognizer.LocationInView(this)             

  if (gestureRecognizer.State == UIGestureRecognizerState.Began)             
    {              
      //Touches began              
   }      
else if (gestureRecognizer.State == UIGestureRecognizerState.Changed)             
   {            
        //Touches Moved              
   }                
 else if (gestureRecognizer.State == UIGestureRecognizerState.Ended)          
       {              
       //Touches ended               
  }            
 }
     }

Regards,
Ashwin

UIScrollView和touchesBegan / touchesEnded等

5 个答案: