中斷animateWithDuration

Question

我有一個倒計時的動畫計時器欄，我希望能夠在滿足某些條件時取消動畫並重置該欄，以使它不會一直到0。類似地，如果確實做到了到0我想調用一個函數。

現在，我只是掛了一個按鈕進行測試。 再次按下該按鈕不會使其完全滑落，但是會在屏幕上彈起，並且完成語句中的print語句始終返回true。 我認為多個動畫正相互疊加。

如何停止動畫？

var countDownBar = UIView()
var button       = UIButton()


override func viewDidLoad() {
    super.viewDidLoad()

    // Place the countDownBar in the center of the view
    countDownBar.frame = CGRectMake(0, 0, 150, 15)
    countDownBar.center = view.center
    countDownBar.backgroundColor = UIColor.blueColor()
    view.addSubview(countDownBar)

    // Add in a button
    button  = UIButton.buttonWithType(UIButtonType.System) as UIButton
    button.frame = CGRectMake(0, 0, 50, 20)
    button.center = CGPointMake(view.center.x, view.center.y + 30)
    button.backgroundColor = UIColor.lightGrayColor()
    button.setTitle("button", forState: UIControlState.Normal)
    button.addTarget(self, action: "buttonAction:", forControlEvents: UIControlEvents.TouchUpInside)
    view.addSubview(button)

}

// Do this when the button is pressed
func buttonAction (sender: UIButton) {

    // Shrink the bar down to 0 width
    UIView.animateWithDuration(3.0,
        animations: ({

            self.countDownBar.frame = CGRectMake(self.countDownBar.frame.minX, self.countDownBar.frame.minY, 0, self.countDownBar.frame.height)

        }),
        completion: {finished in

            // When finished, reset the bar to its original length
            self.countDownBar.frame = CGRectMake(0, 0, 150, 15)
            self.countDownBar.center = self.view.center

            // Display if completed fully or interrupted
            if finished {
                print("animation finished")
            } else {
                print("animation interrupted")
            }
    })
}

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

Answer 1

如果我正確地理解了您的問題，那么在新的usingSpringWithDamping動畫調用中將選項設置為AllowUserInteration可以做到這一點。

animateWithDuration:delay:usingSpringWithDamping:initialSpringVelocity:options:animations:completion:

此外，來自WWDC 2014的構建可中斷和響應式交互的會話可在以下位置進行討論： https : //developer.apple.com/videos/wwdc/2014/可能是有用的資源（它們詳細解釋了它是如何工作的）。