Ios 自定义UIView类未按预期设置动画

我有一个自定义的UIView类，它创建了一个红色背景的正方形，我正试图从左边在它上面放一张绿色的正方形幻灯片。我在主视图中有一个按钮，它将我带到上面的屏幕，但绿色屏幕在它上面没有动画。它只出现在最终结果中。我确实知道，当我更改绿色正方形的初始宽度时，我正在创建这些形状，但没有显示动画

MainViewController.swift

private func configureAnimatedButton() {
    //let sampleAnimatedButton
    let sampleAnimatedButton = AnimatedButtonView()
    sampleAnimatedButton.center = CGPoint(x: self.view.frame.size.width  / 2,
                                          y: self.view.frame.size.height / 2)
    self.view.addSubview(sampleAnimatedButton)
    sampleAnimatedButton.animateMiddleLayer() 
}

动画按钮

import Foundation
import UIKit

public class AnimatedButtonView: UIView {
      //initWithFrame to init view from code
    let movingLayer = UIView()
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        setupView()
    }

    //initWithCode to init view from xib or storyboard
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        setupView()
    }
    
    //common func to init our view
    private func setupView() {
        //backgroundColor = .red
        self.frame = CGRect(x: 0, y: 0, width: 300, height: 300)
        self.backgroundColor = .red
        movingLayer.frame = CGRect(x: self.frame.maxX, y: self.frame.minY, width: 0, height: 300)
        movingLayer.backgroundColor = .green
        self.addSubview(movingLayer)
    }
    
    public func animateMiddleLayer() {
        UIView.animate(withDuration: 10.0, delay: 1.2, options: .curveEaseOut, animations: {
            self.layoutIfNeeded()
            var grayLayerTopFrame = self.movingLayer.frame
            grayLayerTopFrame.origin.x = 0
            grayLayerTopFrame.size.width += 300
            self.movingLayer.frame = grayLayerTopFrame
            self.layoutIfNeeded()
        }, completion: { finished in
            print("animated")
        })
    }
}

---

在开始之前，应将

grayLayerTopFrame

移动到

UIView.animate（）

外部。此外，如果只是对帧设置动画，则不需要

layoutifneed

（在有约束时使用）

---

另外，请确保不要在

viewdiload（）

中调用它——此时，视图尚未布局。

您在哪里调用

sampleAnimatedButton.animatemidlayer（）

？@aheze它位于

self.view.addSubView（sampleAnimatedButton）

var grayLayerTopFrame = self.movingLayer.frame
grayLayerTopFrame.origin.x = 0
grayLayerTopFrame.size.width += 300
UIView.animate(withDuration: 10.0, delay: 1.2, options: .curveEaseOut, animations: {
    self.layoutIfNeeded()
    self.movingLayer.frame = grayLayerTopFrame
    self.layoutIfNeeded()
}, completion: { finished in
    print("animated")
})