CABasicAnimation unlimited repeat without HUGE_VALF?

问题

I'm trying to perform auto repeat of my image rotation animation with CABasicAnimation. I have tried to search on web how to set such property but was unable to find that. Is it really no such property for CA animation? I know that you can set some huge value (here) to repeatCount property but hey, why then does UIView animateWithDuration has an option UIViewAnimationOptionRepeat and what the value is hardcoded for it?

回答1:

No, this is the way you're supposed to do it according to the documentation.

Setting this property to HUGE_VALF will cause the animation to repeat forever.

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Update for Swift:

HUGE_VALF is not exposed to Swift. However, my understanding from this page is that HUGE_VALF is intended to be infinity (in fact, INFINITY is defined as HUGE_VALF). Since Swift's FloatingPointType protocol provides a static var infinity, you can simply write

myAnimation.repeatCount = .infinity

回答2:

For swift 3.0 and above

              let rotationAnimation = CABasicAnimation(keyPath: "transform.rotation.z")
          rotationAnimation.fromValue = 0
          rotationAnimation.toValue = CGFloat.pi * 2
          rotationAnimation.duration = 1
          rotationAnimation.repeatCount = .infinity
          holderView.btnRefresh.layer.add(rotationAnimation, forKey: "spinAnimation")

来源：https://stackoverflow.com/questions/7082578/cabasicanimation-unlimited-repeat-without-huge-valf