宽度的CALayer动画

我有一个视图需要添加一层。我成功地添加了图层,但现在我想做动画,因为它的宽度意味着图层从“开始”标签开始填充,并在“等待…”结束标签我试着添加动画 卡巴斯基化 它从头开始,但没有正确填充。请查看视频了解更多信息。

func startProgressAnimation()
    {
        self.ivStarted.isHighlighted = true
        let layer = CALayer()
        layer.backgroundColor = #colorLiteral(red: 0.4980392157, green: 0.8352941176, blue: 0.1921568627, alpha: 1)
        layer.masksToBounds = true

        layer.frame = CGRect.init(x: self.viewStartedAwaited.frame.origin.x, y: self.viewStartedAwaited.frame.origin.y, width: 0.0, height: self.viewStartedAwaited.frame.height)
        self.ivStarted.layer.addSublayer(layer)

        CATransaction.begin()

        let boundsAnim:CABasicAnimation = CABasicAnimation(keyPath: "bounds.size.width")
        boundsAnim.fromValue = NSNumber.init(value: 0.0)
        boundsAnim.byValue = NSNumber.init(value: Float(self.viewStartedAwaited.frame.size.width / 2.0))
        boundsAnim.toValue = NSNumber.init(value: Float(self.viewStartedAwaited.frame.size.width))
        let anim = CAAnimationGroup()
        anim.animations = [boundsAnim]
        anim.isRemovedOnCompletion = false
        anim.duration = 5
        anim.fillMode = kCAFillModeBoth

        CATransaction.setCompletionBlock{ [weak self] in
            self?.ivAwaited.isHighlighted = true
        }


        layer.add(anim, forKey: "bounds.size.width")
        CATransaction.commit()

    }

下面是我用这段代码实现的视频。 https://streamable.com/h6tpp

不妥

正确形象