Question

在ViewController.Swift中，我设法将一个框从一个点设置为另一个点。我认为循环这很容易，所以框会动画到一个点，然后动画回到原来的位置，然后再循环。我已设法将对象移动到一个位置并在“完成”中再次将其移回，但这并不会使我循环。如何实现这一目标？

我想也许这可行，但老实说我不知道：

let boxmoves = [CGRect(x: 120, y: 220, width: 100, height: 100), CGRect(x: 120, y: 120, width: 100, height: 100)]
for boxmove in boxmoves {
    coloredSquare.frame = boxmove
}

我如何根据设备宽度对中心（我假设涉及一些数学？）？

我的代码：

let coloredSquare = UIView()

coloredSquare.backgroundColor = UIColor.blueColor()

coloredSquare.frame = CGRect(x: 120, y: 120, width: 100, height: 100)

self.view.addSubview(coloredSquare)

// found repeate but this will not animate as I want.
//UIView.animateWithDuration(2.0, delay: 0.2, options: UIViewAnimationOptions.Repeat, animations: {
UIView.animateWithDuration(2.0, animations: {

    coloredSquare.frame = CGRect(x: 120, y: 220, width: 100, height: 100)

    }, completion: { finished in
        UIView.animateWithDuration(2.0, animations: {
        coloredSquare.frame = CGRect(x: 120, y: 120, width: 100, height: 100)
        })
})

Answer 1

无需执行完成块方法，只需使用动画选项参数：

针对Swift 3.0进行了更新

UIView.animate(withDuration: 2.0, delay: 0, options: [.repeat, .autoreverse], animations: {

    coloredSquare.frame = CGRect(x: 120, y: 220, width: 100, height: 100)

}, completion: nil)

如果由于某种原因您想稍后停止动画，请使用：

coloredSquare.layer.removeAllAnimations()

Answer 2

UIView.animate(withDuration: 3.0,
                           delay: 0.0,
                           options: [.curveLinear, .repeat],
                           animations: { () -> Void in
                           coloredSquare.frame = CGRect(x: 120, y: 220, width: 100, height: 100)

}, completion: { (finished: Bool) -> Void in

})

UIView.animateWithDuration快速循环动画

2 个答案: