目的是用動畫讓Label移動並劃出軌跡
但是再次實行後無法消除上次留下的軌跡
用setNeedsLayout或setNeedsDisplay都無效
另外還想問問還有什麼方式可以不使用CA開頭的物件來作動畫效果
因為裡面的keyPath官方文件都沒有相關資料可查效果
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)