CABasicAnimation autoreverse 快两倍

Question

我正在使用此代码添加带自动反转功能的脉冲圈：

let scaleAnimation = CABasicAnimation(keyPath: "transform.scale")        
scaleAnimation.duration = 6
scaleAnimation.repeatCount = 200
scaleAnimation.autoreverses = true
scaleAnimation.fromValue = 0.1
scaleAnimation.toValue = 0.8
scaleAnimation.timingFunction = CAMediaTimingFunction(controlPoints: 0.42, 0.0, 0.58, 1.0)
animationView.layer.add(scaleAnimation, forKey: "scale")

我想在这里做的是：

运行动画 fromValue = 0.1 toValue = 0.8 在 2x speed, 并向后动画 fromValue = 0.8 toValue = 0.1 在 1x speed.

有没有简单的方法可以做到这一点？

Answer 1

您有两种方法可以做到这一点：

CAKeyframeAnimation（最适合你的选择）：

专为使用多个关键帧对单个 keyPath 进行动画处理而设计，每个间隔都有自定义 timeFunctions。正是您所需要的

let scaleAnimation = CAKeyframeAnimation(keyPath: "transform.scale")
scaleAnimation.duration = 18 // 6 seconds for the first part, 12 for the second
scaleAnimation.repeatCount = 200
scaleAnimation.values = [0.1, 0.8, 0.1] // make sure first and last values are equal in order to get seamless animation
scaleAnimation.keyTimes = [0, 0.333, 1] // keyframes scaled to [0; 1] interval
scaleAnimation.timingFunctions = [
    CAMediaTimingFunction(controlPoints: 0.42, 0.0, 0.58, 1.0), //first interval
    CAMediaTimingFunction(controlPoints: 0.58, 0.0, 0.42, 1.0)  //second interval (reversed)
]
layer.add(scaleAnimation, forKey: nil)

CAAnimationGroup（一种解决方法）

旨在为单个图层对动画进行分组（可能具有不同的 keyPaths）

let scaleUpAnimation = CAKeyframeAnimation(keyPath: "transform.scale")
//setup first animation as you did

let scaleDownAnimation = CAKeyframeAnimation(keyPath: "transform.scale")
//setup second animation

let groupAnimation = CAAnimationGroup()
groupAnimation.animations = [scaleUpAnimation, scaleDownAnimation]
//setup group if needed
layer.add(groupAnimation, forKey: nil)

CABasicAnimation autoreverse 快两倍

CABasicAnimation autoreverse twice as fast

animation

core-animation

cabasicanimation

ios

swift