UIViewAnimationOptions.TransitionFlipFromLeft 第二次不显示 UIView

Question

我正在尝试翻转两个 UIViews。我尝试以编程方式使用翻转 UIView 并且效果很好。但是当我尝试翻转我在 storyboard 中创建的 UIView 时它不起作用，第一次它翻转 UIView 但第二次它翻转空白 UiViews？任何人都知道我的代码中是否有任何错误？

在这张图片中，左上角 Debug view Hierarchy 图片是动画按钮之前的图片，左下角 Debug view Hierarchy 图片是动画图片之后的图片。

当我第二次为 UIView 设置动画时，它像下图这样翻转。

class ViewController: UIViewController {

    @IBOutlet var container: UIView!
    @IBOutlet var blueSquare : UIView!
    @IBOutlet var redSquare : UIView!

    override func viewDidLoad() {
        super.viewDidLoad()

    }

    @IBAction func animateButtonTapped(sender: AnyObject) {
        // create a 'tuple' (a pair or more of objects assigned to a single variable)
        var views : (frontView: UIView, backView: UIView)

        if ((self.redSquare.superview) != nil) {
            views = (frontView: self.redSquare, backView: self.blueSquare)
        }
        else {
            views = (frontView: self.blueSquare, backView: self.redSquare)
        }

        // set a transition style
        let transitionOptions = UIViewAnimationOptions.TransitionFlipFromLeft

        // with no animation block, and a completion block set to 'nil' this makes a single line of code
        UIView.transitionFromView(views.frontView, toView: views.backView, duration: 1.0, options: transitionOptions, completion: nil)

    }
}

Programmatically That code is perfectly works.

let container = UIView()
let redSquare = UIView()
let blueSquare = UIView()

override func viewDidLoad() {
    super.viewDidLoad()

    // set container frame and add to the screen
    self.container.frame = CGRect(x: 60, y: 60, width: 200, height: 200)
    self.view.addSubview(container)

    // set red square frame up
    // we want the blue square to have the same position as redSquare 
    // so lets just reuse blueSquare.frame
    self.redSquare.frame = CGRect(x: 0, y: 0, width: 200, height: 200)
    self.blueSquare.frame = redSquare.frame

    // set background colors
    self.redSquare.backgroundColor = UIColor.redColor()
    self.blueSquare.backgroundColor = UIColor.blueColor()

    // for now just add the redSquare
    // we'll add blueSquare as part of the transition animation 
    self.container.addSubview(self.redSquare)   
}

@IBAction func animateButtonTapped(sender: AnyObject) {

    // create a 'tuple' (a pair or more of objects assigned to a single variable)
    var views : (frontView: UIView, backView: UIView)

    if((self.redSquare.superview) != nil){
        views = (frontView: self.redSquare, backView: self.blueSquare)
    }
    else {
        views = (frontView: self.blueSquare, backView: self.redSquare)
    }

    // set a transition style
    let transitionOptions = UIViewAnimationOptions.TransitionFlipFromLeft

    // with no animation block, and a completion block set to 'nil' this makes a single line of code  
    UIView.transitionFromView(views.frontView, toView: views.backView, duration: 1.0, options: transitionOptions, completion: nil)

}

UPDATE

var check = true
 @IBAction func animateButtonTapped(sender: AnyObject) {
    // create a 'tuple' (a pair or more of objects assigned to a single variable)
    var views : (frontView: UIView, backView: UIView)

    if (check == true) {

        views = (frontView: self.redSquare, backView: self.blueSquare)
        check = false
    }
    else {
        views = (frontView: self.blueSquare, backView: self.redSquare)
        check = true
    }

    // set a transition style
    let transitionOptions : UIViewAnimationOptions = [UIViewAnimationOptions.TransitionFlipFromLeft, UIViewAnimationOptions.ShowHideTransitionViews]
    // with no animation block, and a completion block set to 'nil' this makes a single line of code
    UIView.transitionFromView(views.frontView, toView: views.backView, duration: 1.0, options: transitionOptions, completion: nil)

}

Answer 1

啊，在情节提要中，我看到您将两个视图都添加到了容器中，但在代码中您只添加了红方块。也许从情节提要中的容器中删除 bluesquare？

Answer 2

transitionFromView 的默认行为是在动画后删除视图。

let transitionOptions: UIViewAnimationOptions = [.TransitionFlipFromLeft, .ShowHideTransitionViews]

来自文档：https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIView_Class/#//apple_ref/swift/struct/c:@E@UIViewAnimationOptions

ShowHideTransitionViews

When present, this key causes views to be hidden or shown (instead of removed or added) when performing a view transition. Both views must already be present in the parent view’s hierarchy when using this key. If this key is not present, the to-view in a transition is added to, and the from-view is removed from, the parent view’s list of subviews.

UIViewAnimationOptions.TransitionFlipFromLeft 第二次不显示 UIView

UIViewAnimationOptions.TransitionFlipFromLeft not show UIView second time

objective-c

uiviewanimation

ios

swift

swift2