CAShapeLayer’s strokeEnd doesn’t animate

问题:

This is the code I’m using to animate my CAShapeLayer:

_progressBarLayer.strokeEnd = CGFloat(_progressToDrawForProgress(progress))  let progressAnimation = CABasicAnimation(keyPath: "strokeEnd") progressAnimation.duration = CFTimeInterval(1.0) progressAnimation.fromValue = CGFloat(self.progress) progressAnimation.toValue = _progressBarLayer.strokeEnd progressAnimation.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseIn)  _progressBarLayer.addAnimation(progressAnimation, forKey: "progressAnimation") 

I’ve tested using the delegate to see if the animation plays, and it does. Logging start and stop in the right place.

This code is in a setProgress(progress: CGFloat, animated: Bool) function and runs if animated is true.

Is there anything glaringly obvious here?

回答1:

Long answer: It turns out that the animation wasn’t playing because of something being drawn above the CAShapeLayer using quartz, so what I thought was the CAShapeLayer (that should be animated) was actually a Quartz drawing of that same layer.

Short answer: Don’t draw to the graphics context with Quartz

文章来源: CAShapeLayer’s strokeEnd doesn’t animate