ios - Swift:是否可以从堆栈中删除 View Controller？

Question

我找到了一个 Github 存储库，用户在其中创建了一个启动动画，就像在 Twitter 应用程序中一样:This

如果图标是实心形状并位于屏幕中央，效果最佳。

我的问题是我可以将我的图标居中，因为它是如何设计的。因此，当我的动画完成时，应用程序仍会在屏幕上留下一些来自先前制作动画的 View Controller 的 mask 。

那么是否可以在动画完成并且应用程序点击 TableView View Controller 后完全删除该 View Controller ？

这是我的代码:

self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
        self.window!.backgroundColor = UIColor(red: 241/255, green: 196/255, blue: 15/255, alpha: 1)
        self.window!.makeKeyAndVisible()

        // rootViewController from StoryBoard
        let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
        var navigationController = mainStoryboard.instantiateViewControllerWithIdentifier("navigationController") as! UIViewController
        self.window!.rootViewController = navigationController

        // logo mask
        navigationController.view.layer.mask = CALayer()
        navigationController.view.layer.mask.contents = UIImage(named: "logo.png")!.CGImage
        navigationController.view.layer.mask.bounds = CGRect(x: 0, y: 0, width: 10, height: 10)
        navigationController.view.layer.mask.anchorPoint = CGPoint(x: 0.5, y: 0.5)
        navigationController.view.layer.mask.position = CGPoint(x: navigationController.view.frame.width / 2, y: navigationController.view.frame.height / 2)

        // logo mask background view
        var maskBgView = UIView(frame: navigationController.view.frame)
        maskBgView.backgroundColor = UIColor.whiteColor()
        navigationController.view.addSubview(maskBgView)
        navigationController.view.bringSubviewToFront(maskBgView)

        // logo mask animation
        let transformAnimation = CAKeyframeAnimation(keyPath: "bounds")
        transformAnimation.delegate = self
        transformAnimation.duration = 1
        transformAnimation.beginTime = CACurrentMediaTime() + 1 //add delay of 1 second
        let initalBounds = NSValue(CGRect: navigationController.view.layer.mask.bounds)
        let secondBounds = NSValue(CGRect: CGRect(x: 0, y: 0, width: 50, height: 50))
        let finalBounds = NSValue(CGRect: CGRect(x: 0, y: 0, width: 2000, height: 2000))
        transformAnimation.values = [initalBounds, secondBounds, finalBounds]
        transformAnimation.keyTimes = [0, 0.5, 1]
        transformAnimation.timingFunctions = [CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut), CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseOut)]
        transformAnimation.removedOnCompletion = false
        transformAnimation.fillMode = kCAFillModeForwards
        navigationController.view.layer.mask.addAnimation(transformAnimation, forKey: "maskAnimation")

        // logo mask background view animation
        UIView.animateWithDuration(0.1,
            delay: 1.35,
            options: UIViewAnimationOptions.CurveEaseIn,
            animations: {
                maskBgView.alpha = 0.0
            },
            completion: { finished in
                maskBgView.removeFromSuperview()
        })

        // root view animation
        UIView.animateWithDuration(0.25,
            delay: 1.3,
            options: UIViewAnimationOptions.TransitionNone,
            animations: {
                self.window!.rootViewController!.view.transform = CGAffineTransformMakeScale(1.05, 1.05)
            },
            completion: { finished in
                UIView.animateWithDuration(0.3,
                    delay: 0.0,
                    options: UIViewAnimationOptions.CurveEaseInOut,
                    animations: {
                        self.window!.rootViewController!.view.transform = CGAffineTransformIdentity
                    },
                    completion: nil
                )
        })

这个问题在 iPad 上更严重，因为屏幕更大 = 屏幕上留下更多遮蔽。

Answer 1

动画完成后需要移除 mask 。

    UIView.animateWithDuration(0.25,
        delay: 1.3,
        options: UIViewAnimationOptions.TransitionNone,
        animations: {
            self.window!.rootViewController!.view.transform = CGAffineTransformMakeScale(1.05, 1.05)
        },
        completion: { finished in
            UIView.animateWithDuration(0.3,
                delay: 0.0,
                options: UIViewAnimationOptions.CurveEaseInOut,
                animations: {
                    self.window!.rootViewController!.view.transform = CGAffineTransformIdentity
                },
                completion: { 
                     // ADDED THIS LINE
                     self.window!.rootViewController!.view.layer.mask = nil
                }
            )
    })