ios - 使用动画问题缩小按钮的宽度

Question

我想在我的项目中复制这个动画

所以我尝试的是:

1. 转换比例 X ..但问题是它也会缩小按钮的标题。

   self.transform = CGAffineTransform.identity
   UIView.animate(withDuration: duration, delay: delayTime,
                  usingSpringWithDamping: 0.7,
                  initialSpringVelocity: 0.7,
                  options: [.curveEaseIn],
                  animations: {
                   self.transform = CGAffineTransform(scaleX: 0.5, y: 1.0)
       }, completion: nil)
   

   这就是它给出的(按钮的标题也缩小了)

   

2. CASpringAnimation的使用

   let shrinkAnim = CASpringAnimation(keyPath: "bounds.size.width")
   shrinkAnim.damping = 0.7
   shrinkAnim.initialVelocity = 0.7
   shrinkAnim.fromValue = frame.width
   shrinkAnim.toValue = width
   shrinkAnim.dura[![enter image description here][3]][3]tion = duration
   shrinkAnim.timingFunction = getTimingFunction(curve: curve)
   shrinkAnim.fillMode = kCAFillModeForwards
   shrinkAnim.isRemovedOnCompletion = false
   layer.add(shrinkAnim, forKey: shrinkAnim.keyPath)
   

   所以它可以改变标题的宽度和位置

所以我的问题是出了什么问题或者我需要添加什么来复制第一张图片？

My constraints for button is pinned to left, right and bottom edges and fix height. and more thing is I am making a class for this so I cant change constants because I have to use this in many screens .. so I want one stop solution.

Answer 1

不要使用 CGAffineTransform，而是采用 NSLayoutConstraint 属性 socket 作为 Button 的 width 并更改其 constant在动画 block /闭包中。

UIView.animate(withDuration: duration, delay: delayTime,
           usingSpringWithDamping: 0.7,
           initialSpringVelocity: 0.7,
           options: [.curveEaseIn],
           animations: {
            self.buttonWidthConstraint.constant = desired_width_here
}, completion: nil)