iOS动画-UIView动画(transform)

https://www.jianshu.com/p/3f21e81e09dd
https://www.jianshu.com/p/3f21e81e09dd

duration
isRemovedOnCompletion
autoreverses
repeatCount HUGE
fillMode
keyTimes
calculationMode 添加上计算模式属性，让动画更平滑
values
path

六. CASpringAnimation（弹簧动画）

      let redView = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
        redView.backgroundColor = .red
        redView.center = view.center
        view.addSubview(redView)
        
        
        let animation = CASpringAnimation(keyPath: "transform.scale")
        animation.beginTime = CACurrentMediaTime() + 3
        animation.mass = 0.1 //设置质量，质量越大，惯性越大
        animation.damping = 1//设置阻尼系数，阻尼系数越大，停止越快
        animation.stiffness = 100 //设置刚性系数，刚性系数越大，运动越快
        animation.initialVelocity = 0.3 //初始速率
        animation.toValue = 2.0
        animation.isRemovedOnCompletion = false
        animation.repeatCount = HUGE
        animation.autoreverses = true
        animation.fillMode = .forwards
        animation.timingFunction = CAMediaTimingFunction(name: CAMediaTimingFunctionName.easeInEaseOut)
        animation.duration = animation.settlingDuration//设置动画时长
        redView.layer.add(animation, forKey: "scale")

https://www.jianshu.com/p/91b0cb25d4cb