CABasicAnimation：从左到右

Question

使用以下代码，我可以从左到右为CALayer设置动画

let imageLayer = CALayer()
imageLayer.frame = CGRect(x: 0, y: 500, width: 100, height: 70)
imageLayer.contents = UIImage(named: "first_image")?.cgImage

let animation = CABasicAnimation()
animation.keyPath = "position.x"
animation.fromValue = 100
animation.toValue = 300
animation.duration = 3
animation.fillMode = kCAFillModeForwards
animation.isRemovedOnCompletion = true
animation.repeatCount = 2
imageLayer.add(animation, forKey: "basic")

self.view.layer.addSublayer(imageLayer)

我想要做的是，

  

周期：1 - “first_image”将从左向右移动

并在

  

周期：2 - “second_image”（这是另一张图片）将从左侧移动   像上一个周期一样正确。

这里周期：1 + 周期：2 实际上是一个动画，我希望这个动画多次发生。怎么做到这一点？ 任何帮助将不胜感激。

Answer 1

因为你需要从左到右＆amp;反之亦然动画，您也可以使用UIView.anima..进行动画制作。

     let testViewTowardsLeft = UIView(frame: CGRect(x: 0, y: 150, width: 50, height: 50))
    testViewTowardsLeft.backgroundColor = .red
    view.addSubview(testViewTowardsLeft)
    UIView.animate(withDuration: 1, delay: 0, options: .repeat, animations: {Bool in
        testViewTowardsLeft.frame = CGRect(x: 100, y: 150, width: 50, height: 50)

    }, completion: nil)


    let testViewTowardsRight = UIView(frame: CGRect(x: 100, y: 100, width: 50, height: 50))
    testViewTowardsRight.backgroundColor = .red
    view.addSubview(testViewTowardsRight)
    UIView.animate(withDuration: 1, delay: 0, options: .repeat, animations: {Bool in
        testViewTowardsRight.frame = CGRect(x: 0, y: 100, width: 50, height: 50)

    }, completion: nil)