Ios 动画CALayer边界alpha

我有一个带边框的

ui视图

（颜色：绿色，宽度：10）

我正在尝试将边界的alpha（在循环中）从值1.0设置为值0.2-然后返回到1.0-然后返回到0.2等等

但是

CALayer

没有

borderAlpha

属性，所以我不确定如何才能做到这一点

我尝试过此代码，但无效：

UIView.animate(withDuration: 1, delay: 0, options: [.repeat, .autoreverse], animations: {
    self.layer.borderColor = UIColor(cgColor: self.layer.borderColor!).withAlphaComponent(0.2).cgColor
}, completion: nil)

有人知道我怎么做吗

---

谢谢大家!

更新并简化了。使用

CALayer

创建边界层，然后使用

CABasicAnimation

实现淡入淡出效果：

class BorderView: UIView {
    private var boarderLayer:CALayer?
    private let animationKey = "opacityAnimation"

    override public var frame: CGRect {
        didSet{
            self.updateBorder()
        }
    }

    func updateBorder() {
        if boarderLayer == nil {
            boarderLayer = CALayer()
            boarderLayer?.borderColor = UIColor.red.cgColor
            boarderLayer?.borderWidth = 5.0
            self.layer.addSublayer(boarderLayer!)
        }

        boarderLayer?.frame = self.bounds

        if (boarderLayer?.animation(forKey: animationKey) == nil) {
            self.addAnimiation(layer: boarderLayer!,increasing:true)
        }
    }

    func addAnimiation(layer:CALayer,increasing:Bool) {
        CATransaction.begin()

        CATransaction.setCompletionBlock{ [weak self] in
            self?.addAnimiation(layer: layer,increasing:!increasing)
        }

        let animation = CABasicAnimation(keyPath: "opacity")
        if increasing {
            layer.opacity = 0.2
            animation.fromValue = 1.0
            animation.toValue = 0.2
        }
        else{
            layer.opacity = 1.0
            animation.fromValue = 0.2
            animation.toValue = 1.0
        }
        animation.duration = 1.0
        layer.add(animation, forKey: animationKey)

        CATransaction.commit()
    }
}

结果是：

尝试使用此

class animateStack: UIViewController {

    @IBOutlet weak var animateView: UIView!{
        didSet{
            animateView.layer.borderColor = UIColor.black.cgColor
            animateView.layer.borderWidth = 10
        }
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        animateBorderAlpha()
    }

    private func animateBorderAlpha(){
        /// First Animation
        let animation = CABasicAnimation(keyPath: "borderColor")
        animation.beginTime = 0
        animation.toValue = UIColor.black.withAlphaComponent(0.1).cgColor
        animation.fromValue = UIColor.black.cgColor
        animation.duration = 2

        /// Second Animation
        let animation1 = CABasicAnimation(keyPath: "borderColor")
        animation1.toValue = UIColor.black.cgColor
        animation1.fromValue = UIColor.black.withAlphaComponent(0.1).cgColor
        animation1.beginTime = animation.beginTime + animation.duration
        animation.duration = 4

        /// Animation Group
        let borderColorAnimation: CAAnimationGroup = CAAnimationGroup()
        borderColorAnimation.animations = [animation, animation1]
        borderColorAnimation.duration = animation.duration + animation1.duration
        borderColorAnimation.repeatCount = Float.greatestFiniteMagnitude
        self.animateView.layer.add(borderColorAnimation, forKey: "borderColor")
    }

}

更新

class animateViewClass: NSObject {
    class func animateBorderAlpha(_ view: UIView){
        /// First Animation
        let animation = CABasicAnimation(keyPath: "borderColor")
        animation.beginTime = 0
        animation.toValue = UIColor.black.withAlphaComponent(0.1).cgColor
        animation.fromValue = UIColor.black.cgColor
        animation.duration = 2

        /// Second Animation
        let animation1 = CABasicAnimation(keyPath: "borderColor")
        animation1.toValue = UIColor.black.cgColor
        animation1.fromValue = UIColor.black.withAlphaComponent(0.1).cgColor
        animation1.beginTime = animation.beginTime + animation.duration
        animation.duration = 4

        /// Animation Group
        let borderColorAnimation: CAAnimationGroup = CAAnimationGroup()
        borderColorAnimation.animations = [animation, animation1]
        borderColorAnimation.duration = animation.duration + animation1.duration
        borderColorAnimation.repeatCount = Float.greatestFiniteMagnitude
        view.layer.add(borderColorAnimation, forKey: "borderColor")
    }
}

    animateViewClass.animateBorderAlpha(viewName)
    /// Case of Subclass UIView
    animateViewClass.animateBorderAlpha(self)

用法

class animateViewClass: NSObject {
    class func animateBorderAlpha(_ view: UIView){
        /// First Animation
        let animation = CABasicAnimation(keyPath: "borderColor")
        animation.beginTime = 0
        animation.toValue = UIColor.black.withAlphaComponent(0.1).cgColor
        animation.fromValue = UIColor.black.cgColor
        animation.duration = 2

        /// Second Animation
        let animation1 = CABasicAnimation(keyPath: "borderColor")
        animation1.toValue = UIColor.black.cgColor
        animation1.fromValue = UIColor.black.withAlphaComponent(0.1).cgColor
        animation1.beginTime = animation.beginTime + animation.duration
        animation.duration = 4

        /// Animation Group
        let borderColorAnimation: CAAnimationGroup = CAAnimationGroup()
        borderColorAnimation.animations = [animation, animation1]
        borderColorAnimation.duration = animation.duration + animation1.duration
        borderColorAnimation.repeatCount = Float.greatestFiniteMagnitude
        view.layer.add(borderColorAnimation, forKey: "borderColor")
    }
}

    animateViewClass.animateBorderAlpha(viewName)
    /// Case of Subclass UIView
    animateViewClass.animateBorderAlpha(self)

---

我使用的是

UIView

的子类，而不是

UIViewController

您需要在UIView中添加此动画，比如self.yourViewName.layer.add（borderColorAnimation，forKey:“borderColor”）///第二个动画动画。持续时间=4（可能是动画1？）我使用的是

UIView

的子类，而不是

UIViewController

你应该在那里找到答案：@Aamir，我认为它们是不同的情况。这一个是：A动画到B，B动画到A。你的链接：A动画到B，A动画到B。。。