动画起源 iOS

Posted 2023-03-14

【中文标题】动画起源 iOS

【英文标题】：Animation origin iOS

【发布时间】：2016-07-08 14:45:48

【问题描述】：

我一直在尝试创建一个在不改变原点的情况下增加视图高度的动画（左上边缘和右上边缘保持在同一位置）

import UIKit
class SampRect: UIView 
var res : CGRect?
override init(frame: CGRect) 
    super.init(frame: frame)
    self.backgroundColor = UIColor(red: 0.91796875, green: 0.91796875, blue: 0.91796875, alpha: 1)
    self.layer.cornerRadius = 5

    let recognizer = UITapGestureRecognizer(target: self, action:#selector(SampRect.handleTap(_:)))
    self.addGestureRecognizer(recognizer)




func handleTap(recognizer : UITapGestureRecognizer) 

    let increaseSize = CABasicAnimation(keyPath: "bounds")
    increaseSize.delegate = self
    increaseSize.duration = 0.4
    increaseSize.fromValue = NSValue(CGRect: frame)
    res = CGRect(x: self.frame.minX, y: self.frame.minY, width: frame.width, height: self.frame.height + 10)
    increaseSize.toValue = NSValue(CGRect: res!)

    increaseSize.fillMode = kCAFillModeForwards
    increaseSize.removedOnCompletion = false

    layer.addAnimation(increaseSize, forKey: "bounds")




override func animationDidStop(anim: CAAnimation, finished flag: Bool) 
    self.frame = res!



required init?(coder aDecoder: NSCoder) 
    fatalError("init(coder:) has not been implemented")
   

但动画会从中间增大尺寸（将顶边向上推，底边向下推） 我错过了什么？

【问题讨论】：

要这样做，您需要为视图设置一个锚点。您是否尝试过在animateWithDuration 中执行此操作？然后，您可以将框架显式设置为您想要的任何内容，它会准确地保持这一点（无需为您估算内容）。

【参考方案1】：

你可以试试这个。

        let newheight:CGFloat = 100.0
        UIView.animateWithDuration(0.5) 

            self.frame = CGRectMake(self.frame.origin.x, self.frame.origin.y, self.frame.size.width, newheight)