Swift，从数组中连续播放多个动画？

Question

抱歉，我是 swift 的新手。我无法让每个动画连续播放而不是同时播放。我试过使用 sleep()，但那似乎不允许播放动画。这就是我找到要播放的动画的方式。

for number in sequence {
    switch number {
    case 1:
        print("blue")
        animateB()
    case 2:
        print("green")
        animateG()
    case 3:
        print("magenta")
        animateM()
    case 4:
        print("orange")
        animateO()
    case 5:
        print("yellow")
        animateY()
    case 6:
        print("red")
        animateR()
    case 7:
        print("purple")
        animateP()
    case 8:
        print("cyan")
        animateC()
    default:
        print("error")
    }
}

这是我用来制作动画的功能之一。我意识到这也可能非常低效，但不确定如何使功能更好。

private func animateB(){
    let animation = CABasicAnimation(keyPath: "transform.scale")
    animation.toValue = 1.3
    animation.duration = 0.5
    animation.autoreverses = true
    self.pulsatingB.add(animation, forKey: "pulsing")
}

如果有任何帮助，我们将不胜感激。 :)

Answer 1

您可以使用 CATransaction 链接 CAAnimation:

class ViewController: UIViewController {

    // The animations, to be applied in order
    var animationQueue = [() -> Void]()

    @IBAction func animate(_ sender: Any) {

        animationQueue.removeAll()

        // Build the animation queue
        for number in sequence {
            switch number {
            case 1:
                print("blue")
                animationQueue.append(animateB)
            case 2:
                print("green")
                animationQueue.append(animateG)
            // ....
            default:
                break
            }
        }

        // Start the animation
        applyNextAnimation()
    }

    func applyNextAnimation() {
        guard !animationQueue.isEmpty else { return }
        let animation = animationQueue.removeFirst()

        // When an animation completes, call this function again to apply the next animation
        CATransaction.begin()
        CATransaction.setCompletionBlock({ self.applyNextAnimation() })
        animation()
        CATransaction.commit()
    }

}