目的是用动画让Label移动并划出轨迹
但是再次实行后无法消除上次留下的轨迹
用setNeedsLayout或setNeedsDisplay都无效
另外还想问问还有什么方式可以不使用ＣＡ开头的物件来作动画效果
因为里面的keyPath官方文件都没有相关资料可查效果
下面是我的code
self.view.setNeedsLayout()
self.view.layer.setNeedsLayout()
let path=UIBezierPath()
...
let anim=CAKeyframeAnimation(keyPath:"position")
anim.path=path.cgPath
anim.repeatCount=1
anim.duration=5.0
self.myLabel.layer.add(anim, forKey: "Path")
let progressLine = CAShapeLayer()
progressLine.path = path.cgPath
progressLine.strokeColor = UIColor.blue.cgColor
progressLine.fillColor = UIColor.clear.cgColor
progressLine.lineWidth = 10.0
let animateStrokeEnd = CABasicAnimation(keyPath: "strokeEnd")
animateStrokeEnd.duration = 5.0
animateStrokeEnd.fromValue = 0.0
animateStrokeEnd.toValue = 1.0
progressLine.add(animateStrokeEnd, forKey: "animate stroke end animation")
self.view.layer.addSublayer(progressLine)