ios - 如何在 CALayer 中为图像制作动画

Question

在我的CALayer中，我正在尝试对图像进行动画处理，但动画层没有显示。我在这里做错了什么:

return CALayer().build {

        let myLayer = CALayer()

        let animation = CAKeyframeAnimation(keyPath: "contents")
        animation.fillMode = kCAFillModeForwards
        animation.duration = 3
        animation.values = TimeLineVC.likeInteractionArray.map {
            $0.cgImage as AnyObject
        }
        animation.repeatCount = 3

        myLayer.frame = $0.bounds
        myLayer.add(animation, forKey: "contents")
        $0.insertSublayer(myLayer, above: $0)
        myLayer.backgroundColor = UIColor.black.cgColor


      }

Answer 1

添加一些属性后它对我有用:

let animation = CAKeyframeAnimation(keyPath: "contents")
        animation.calculationMode = kCAAnimationDiscrete
        animation.duration = 3.0
        animation.repeatCount = .greatestFiniteMagnitude
        animation.autoreverses = false
        animation.values = TimeLineVC.likeInteractionArray.map {$0.cgImage!}
        animation.isRemovedOnCompletion = false
        animation.fillMode = kCAFillModeForwards
        animation.beginTime = 0.0
        $0.add(animation, forKey: "contents")