ios - 在 Swift 中添加 subview 时如何停止动画重置？

Question

我试图让元素在云的位置生成。到目前为止，我已经按照我想要的方式重复制作云动画，但是当我生成一个项目时，云动画会从头开始重置。

添加 subview 时，我有哪些选择？

Here is a gif from the project

override func viewDidLoad() {
    super.viewDidLoad()

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()
    gemCloudImage.center.x = 100
    makeCloudFly()
}

override func viewDidAppear(animated: Bool) {
    super.viewDidAppear(true)
}

func makeCloudFly() {
    UIView.animateWithDuration(6, delay: 1, options: [.Autoreverse, .Repeat], animations: {
        self.gemCloudImage.center.x = self.view.frame.width - 100
        }, completion: nil)
}

@IBAction func buttonTapped(sender: AnyObject) {

    let positionX: CGFloat = gemCloudImage.layer.presentationLayer()!.frame.midX
    let positionY: CGFloat = gemCloudImage.layer.presentationLayer()!.frame.midY
    print(positionX)
    print(positionY)

    let chair = UIImageView()
    chair.image = UIImage(named: "CHAIR1")
    chair.frame = CGRectMake(positionX, positionY, 50, 50)
    chair.frame = CGRect(x:positionX, y:positionY, width:50, height:50)
    self.view.addSubview(chair)

}

Answer 1

将viewDidLayoutSubviews中的代码移动到viewDidLoad中。那应该可以解决您的问题。

每次添加新 subview 时都会调用方法 viewDidLayoutSubviews。