Swift：如何在函数执行之外终止一个函数

Question

我对Swift仍然很陌生。我想知道如何在函数执行之外快速终止动画函数。在下面的情况下，我运行一个动画15秒，但任何时候当用户按下某个按钮时，我希望动画停止并且元素消失。任何关于这个最好的方法的想法？这是功能。

func createTimerAnimation() { 
    // create timer line shapes 

    guard self.timerisActive else { 

     print("in guard 1") 
     return 
    } 

    let screenWidth = (self.view.bounds.width) 
    let screenHeight = (self.view.bounds.height) 

    let timerShapeLeft = drawTimerShape() 
    let timerShapeRight = drawTimerShape() 
    let timerShapeCenter = drawTimerShape() 

    view.addSubview(timerShapeLeft) 
    view.addSubview(timerShapeRight) 
    view.addSubview(timerShapeCenter) 

UIView.animate(withDuration: 14.5, delay: 0.0, options: [.curveEaseOut], animations:{ 
      timerShapeLeft.frame = CGRect (x: (screenWidth/2), y: (screenHeight - 60), width: timerShapeLeft.frame.width, height: (timerShapeLeft.frame.height - 30)) 
      timerShapeRight.frame = CGRect (x: (screenWidth/2), y: (screenHeight - 60), width: timerShapeRight.frame.width, height: (timerShapeRight.frame.height - 30)) 
      timerShapeCenter.frame = CGRect (x: (screenWidth/2), y: (screenHeight - 60), width: timerShapeCenter.frame.width, height: (timerShapeCenter.frame.height)) 
      timerShapeLeft.alpha = 1.0 
      timerShapeRight.alpha = 1.0 
      timerShapeCenter.alpha = 0.4 
      timerShapeLeft.tintColor = self.hexGray 
      timerShapeRight.tintColor = self.hexGray 

      guard self.timerisActive else { 

       print("in guard 1") 
       return 
      } 

Answer 1

动画实际上是由该视图的层处理，这样你可以用CALayer.removeAllAnimations()有其取消：

view.layer.removeAllAnimations()