在animateWithDuration：completion的完成塊中刪除UIView

Question

我正在用animateWithDuration：completion為UIView的某些屬性設置動畫。 這些動畫完成后，我想從他的超級視圖中刪除該視圖。 問題是，如果我在完成塊中添加removeFromSuperView，則根本不會獲得動畫。 我發現的解決方法是刪除dispatch_after內部的視圖。 為什么？

     var loadingView: Loading!  //This is a UIView loaded from a Nib
    let delaySecs: NSTimeInterval = 2
    UIView.animateWithDuration(delaySecs, animations: { () -> Void in
        self.loadingView.cherrysImageView.transform = CGAffineTransformMakeScale(2, 2)
        self.loadingView.cherrysImageView.alpha = 0
    }) { (succeed) -> Void in
        //Can't remove the view here, otherwise i get NO animation
        //self.loadingView.removeFromSuperview()
    }

        //And if i add this instead of removing the view in the completion block, it works as expected
    let delay = delaySecs * Double(NSEC_PER_SEC)
    let time = dispatch_time(DISPATCH_TIME_NOW, Int64(delay))
    dispatch_after(time, dispatch_get_main_queue()) { () -> Void in
        self.loadingView.removeFromSuperview()
    }

Answer 1

動畫完成塊在動畫過程中被多次調用，但是只有當成功為true時，您才應刪除所有內容。

var loadingView: Loading!  //This is a UIView loaded from a Nib
let delaySecs: NSTimeInterval = 2
UIView.animateWithDuration(delaySecs, animations: { () -> Void in
    self.loadingView.cherrysImageView.transform = CGAffineTransformMakeScale(2, 2)
    self.loadingView.cherrysImageView.alpha = 0
}) { (succeed) -> Void in
    if succeed {
        self.loadingView.removeFromSuperview()
    }
}