ios - iOS 中如何重置动画？

Question

这是我的代码:

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    cloud.center.x  -= view.bounds.width
    cloud1.center.x -= view.bounds.width
    cloud2.center.x -= view.bounds.width
    cloud3.center.x -= view.bounds.width
}

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)

    UIView.animate(withDuration: 12) {
        self.cloud.center.x += self.view.bounds.width*2

        UIView.animate(withDuration: 12, delay: 9, options: [],
                       animations: {
                            self.cloud1.center.x += self.view.bounds.width*2
                        },
                       completion: nil
        )
        UIView.animate(withDuration: 12, delay: 18, options: [],
                       animations: {
                            self.cloud2.center.x += self.view.bounds.width*2
                        },
                       completion: nil
        )
        UIView.animate(withDuration: 12, delay: 22, options: [],
                       animations: {
                            self.cloud3.center.x += self.view.bounds.width*2
                        },
                       completion: nil
        )
    }
}

我有一个重做，可以重置页面中的所有内容，除了我的动画之外，它只停留在一个位置。如何重置动画以便再次重新播放动画？

Answer 1

您的动画代码将 4 个云 View 向右移动 self.view.bounds.width*2，方法是将该量添加到它们的中心位置。

要撤消该更改，只需减去相同的金额即可。