我正在尝试每 20 毫秒向给定的 x 和 y 坐标添加一次 CAShapelayer。我希望形状在一秒钟内消失(就像示踪剂一样)。我创建的功能有效,形状在正确的位置创建并消失。但是我留下了额外的形状,使屏幕变得杂乱无章。
func shadowBall (x: CGFloat, y: CGFloat){
let xpos : CGFloat = ((self.frame.width/2) + x)
let ypos : CGFloat = ((self.frame.height/2) + y)
let shadowBall = CAShapeLayer()
let shadowBalllRadius :CGFloat = 4
let shadowBallPath : UIBezierPath = UIBezierPath(ovalInRect: CGRect(x: xpos, y: ypos, width: CGFloat(shadowBalllRadius*2), height: CGFloat(shadowBalllRadius*2)))
shadowBall.path = shadowBallPath.CGPath
shadowBall.fillColor = UIColor.clearColor().CGColor
shadowBall.strokeColor = UIColor.whiteColor().CGColor
shadowBall.lineWidth = 0.5
let animation: CABasicAnimation = CABasicAnimation(keyPath: "strokeColor")
animation.fromValue = UIColor.whiteColor().CGColor
animation.toValue = UIColor.clearColor().CGColor
animation.duration = 1.0;
animation.repeatCount = 0;
animation.removedOnCompletion = true
animation.additive = false
self.layer.addSublayer(shadowBall)
shadowBall.addAnimation(animation, forKey: "strokeColor")
}
最佳答案
问题是当动画结束时,它会将 strokeColor
恢复为原始颜色。您真的应该将原始形状图层的 strokeColor
设置为 clearColor()
,这样,当您完成从 whiteColor()
到clearColor()
,它将保持在 clearColor()
。
您还可以将图层的fillMode
设置为kCAFillModeForwards
,并将removedOnCompletion
设置为false
,这将有图层保留其“动画结束”状态。但我个人只会设置 strokeColor
如上所述,因为使用 true
的 removedOnCompletion
会干扰 animationDidStop
(请参阅下)。
此外,我可能建议您在完成动画后也删除该层,这样它就不会继续消耗内存,尽管它不再可见。
func shadowBall (x: CGFloat, y: CGFloat) {
let xpos: CGFloat = ((self.frame.width/2) + x)
let ypos: CGFloat = ((self.frame.height/2) + y)
let shadowBall = CAShapeLayer()
let shadowBalllRadius: CGFloat = 4
let shadowBallPath = UIBezierPath(ovalInRect: CGRect(x: xpos, y: ypos, width: CGFloat(shadowBalllRadius*2), height: CGFloat(shadowBalllRadius*2)))
shadowBall.path = shadowBallPath.CGPath
shadowBall.fillColor = UIColor.clearColor().CGColor
shadowBall.strokeColor = UIColor.clearColor().CGColor
shadowBall.lineWidth = 0.1
let animation = CABasicAnimation(keyPath: "strokeColor")
animation.fromValue = UIColor.whiteColor().CGColor
animation.toValue = UIColor.clearColor().CGColor
animation.duration = 1.0
animation.repeatCount = 0
animation.removedOnCompletion = true
animation.additive = false
animation.delegate = self
animation.setValue(shadowBall, forKey: "animationLayer")
self.layer.addSublayer(shadowBall)
shadowBall.addAnimation(animation, forKey: "strokeColor")
}
override func animationDidStop(anim: CAAnimation, finished flag: Bool) {
if let layer = anim.valueForKey("animationLayer") as? CALayer {
layer.removeFromSuperlayer()
}
}
关于swift - CAShapelayer 副本,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/37975849/