UIScrollView和touchesBegan / touchesEnded等

Question

我有一个带有两个子视图的UIView，我们称之为视图A

• 一个基本的UIView，称为B
• 一个UIScrollView，叫做C

我在视图A中重写了以下方法

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

当我触摸视图B、touchesBegan:withEvent:和touchesEnded:withEvent:时被调用，但是如果我触摸UIScrollView (查看C)，则不会调用。

我知道这是预期的行为，但我正在努力理解原因。我找不到任何明确的答案。有什么想法吗？

Answer 1

你至少有两个选择：

1)“将userInteractionEnabled设置为滚动视图的NO”。更多信息请访问https://stackoverflow.com/a/25108078/1702413

2)子类UIScrollView --例如，使用此https://dl.dropboxusercontent.com/u/19438780/ClassScrollViewDelegate.zip

更新

为什么？请再读一遍文件：

“因为滚动..它必须知道触摸是否表示要滚动的意图.它暂时拦截一个触下事件.滚动视图取消子视图中的任何跟踪，并执行滚动自身”

和最重要的是： **

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

出发地：ref/doc/uid/TP40006922

Answer 2

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   
}

迅捷版：

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 3

如果有滚动视图，thouchesBegan方法将无法工作，因为如果想滚动，就必须在故事板中启用userInteractionEnabled。如果你成功了，它就会触发。因此，解决方案是使用TapGestureRecognizer，将其添加到viewDidLoad中：

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这个MyTapMethod。

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

这很好用。