Swift：将 UIPanGestureRecognizer 设置为 UIView答案

【问题标题】：Swift : Set UIPanGestureRecognizer to UIViewSwift：将 UIPanGestureRecognizer 设置为 UIView
【发布时间】：2016-01-03 06:42:14
【问题描述】：

我正在尝试将 UIPanGestureRecognizer 设置为特定的 UIView

    self.halfViewBlue.frame = CGRectMake(0, 0, self.bounds.width / 2, self.bounds.height)
    self.halfViewBlue.backgroundColor = UIColor.blueColor()
    halfViewBlue.alpha = 1.0
    self.addSubview(self.halfViewBlue)

    self.halfViewRed.frame = CGRectMake(self.frame.midX, 0, self.bounds.width / 2, self.bounds.height)
    self.halfViewRed.backgroundColor = UIColor.redColor()
    halfViewRed.alpha = 1.0
    self.addSubview(self.halfViewRed)

    //Pan Gesture for Red
    let panGestureRed = UIPanGestureRecognizer()
    panGestureRed.addTarget(self, action: "handlePanRed:")
    self.addGestureRecognizer(panGestureRed)
    self.userInteractionEnabled = true

    //Pan Gesture for Blue
    let panGestureBlue = UIPanGestureRecognizer()
    panGestureBlue.addTarget(self, action: "handlePanBlue:")
    self.addGestureRecognizer(panGestureBlue)
    self.userInteractionEnabled = true

}

func handlePanRed(gesture : UIPanGestureRecognizer){

    if (gesture.state == UIGestureRecognizerState.Changed || gesture.state == UIGestureRecognizerState.Ended){

        let velocity : CGPoint = gesture.velocityInView(halfViewRed)

        //Pan Down
        if(velocity.y > 0){
            print("Panning down")
            hideRedBar()
            produceBlueBar()
        }
        //Pan Up
        if(velocity.y < 0){
            print("panning up")
            hideBlueBar()
            produceRedBar()
        }
    }
}


func handlePanBlue(gesture : UIPanGestureRecognizer){

    if (gesture.state == UIGestureRecognizerState.Changed || gesture.state == UIGestureRecognizerState.Ended){

        let velocity : CGPoint = gesture.velocityInView(halfViewBlue)

        //Pan Down
        if(velocity.y > 0){
            print("Panning down")
            hideBlueBar()
            produceRedBar()
                        }

        if(velocity.y < 0){
            print("panning up")
            hideRedBar()
            produceBlueBar()

        }
    }
}

这里我只是简单地创建了两个 UIView，它们都垂直（相等地）在屏幕上分开。然后我添加了两个 panGestures 和一个函数来跟随它。我的问题是唯一被识别的 panGesture 是“panGestureBlue”，奇怪的是我可以在屏幕的任何部分控制它，而不仅仅是“halfViewBlue”所在的一半。所以我假设两个 panGestures 都被添加到 self.view 而不是它应该放在的 UIView 中，并且正在读入“panGestureBlue”，因为它是在“panGestureRed”之后添加的。而不是“panGestureBlue.addTarget”中的“self”，我尝试放置“halfViewBlue”，但它崩溃了。

我该如何解决这个问题！？

【问题讨论】：

标签： ios iphone swift uiview uipangesturerecognizer

【解决方案1】：

您应该在子视图而不是父视图上添加平移手势，如下所示：

self.halfViewRed.addGestureRecognizer(panGestureRed)
self.halfViewBlue.addGestureRecognizer(panGestureBlue)

【讨论】：