如何暂停和恢复UIView.animateWithDuration

我有一个图像，我使用此代码为viewDidAppear设置动画：

UIView.animateWithDuration(10.5, delay:0.0, options: [], animations:{ self.myImage.transform = CGAffineTransformMakeTranslation(0.0, 200) }, completion: nil) 

我想点击myPauseButton时暂停动画，如果我再次点击它，则恢复动画。

Answer 1

暂停和恢复动画的2个function，我从这里开始转换为Swift。

 func pauseLayer(layer: CALayer) { let pausedTime: CFTimeInterval = layer.convertTime(CACurrentMediaTime(), fromLayer: nil) layer.speed = 0.0 layer.timeOffset = pausedTime } func resumeLayer(layer: CALayer) { let pausedTime: CFTimeInterval = layer.timeOffset layer.speed = 1.0 layer.timeOffset = 0.0 layer.beginTime = 0.0 let timeSincePause: CFTimeInterval = layer.convertTime(CACurrentMediaTime(), fromLayer: nil) - pausedTime layer.beginTime = timeSincePause } 

我有一个按钮来暂停或恢复在viewDidLoad初始化的动画：

 var pause = false override func viewDidAppear(animated: Bool) { super.viewDidAppear(animated) UIView.animateWithDuration(10.5, delay:0.0, options: [], animations:{ self.image.transform = CGAffineTransformMakeTranslation(0.0, 200) }, completion: nil) } @IBAction func changeState() { let layer = image.layer pause = !pause if pause { pauseLayer(layer) } else { resumeLayer(layer) } } 

Answer 2

这是答案的Swift 3版本+我将这些function移到了扩展名

 extension CALayer { func pause() { let pausedTime: CFTimeInterval = self.convertTime(CACurrentMediaTime(), from: nil) self.speed = 0.0 self.timeOffset = pausedTime } func resume() { let pausedTime: CFTimeInterval = self.timeOffset self.speed = 1.0 self.timeOffset = 0.0 self.beginTime = 0.0 let timeSincePause: CFTimeInterval = self.convertTime(CACurrentMediaTime(), from: nil) - pausedTime self.beginTime = timeSincePause } } 

Answer 3

由于iOS 10提供了UIViewPropertyAnimator您可以更轻松地解决问题。

在控制器中创建这些属性：

 var animationPaused = false lazy var animator: UIViewPropertyAnimator = UIViewPropertyAnimator(duration: 10.5, curve: .easeInOut, animations: { self.myImage.transform = CGAffineTransform(translationX: 0.0, y: 200) }) 

将以下代码添加到myPauseButton的tap处理程序中：

 if self.animator.state == .active { // Don't start or pause animation when it finished self.animationPaused = !self.animationPaused self.animationPaused ? self.animator.pauseAnimation() : self.animator.startAnimation() } 

使用以下代码行从viewDidAppear(_ animated: Bool)开始动画：

 self.animationPaused = false self.animator.startAnimation()