swift - preferredStatusBarUpdateAnimation 被忽略

Question

我有 AuthViewController 像这样显示 MainViewController:

let mainVC = MainViewContoller()
mainVC.modalTransitionStyle = .CrossDissolve
authVC.presentViewController(mainVC, animated: true, completion: nil)

我希望 AuthViewController 隐藏状态栏，但 MainViewController 显示，如下所示:

AuthViewController {

    override func preferredStatusBarStyle() -> UIStatusBarStyle {
        return .LightContent
    }

    override func preferredStatusBarUpdateAnimation() -> UIStatusBarAnimation {
        return .Fade
    }

    override func prefersStatusBarHidden() -> Bool {
        return false
    }
}

MainViewController {

    override func preferredStatusBarStyle() -> UIStatusBarStyle {
        return .LightContent
    }

    override func preferredStatusBarUpdateAnimation() -> UIStatusBarAnimation {
        return .Fade
    }

    override func prefersStatusBarHidden() -> Bool {
        return false
    }
}

状态栏出现，但是 preferredStatusBarUpdateAnimation() 覆盖被忽略。状态栏出现时没有动画。

我只能通过将 MainViewController 上的 prefersStatusBarHidden 设置为 true 直到 viewDidAppear，然后调用这个:

UIView.animateWithDuration(0.3) {
    self.setNeedsStatusBarAppearanceUpdate()
}

我不想每次都调用它。我做错了什么？

Answer 1

也在寻找解决方案。但是，您似乎已经获得了一半的解决方案。您必须为变量设置覆盖，但对我来说最好的做法是为每个覆盖创建一个私有(private)变量对，并让每个覆盖返回它各自的私有(private)变量(见下文)。然后，您将更改私有(private)变量并调用 setNeedsStatusBarAppearanceUpdate。

另外，您需要将 info.plist 中的 View controller-based status bar appearance 设置为 YES。否则，它仍将依赖遗留的 UIApplication.shared... 方法。

这是一个片段:

override var preferredStatusBarUpdateAnimation: UIStatusBarAnimation {
    get {
        return .slide
    }
}

private var statusBarStyle : UIStatusBarStyle = .default

override var preferredStatusBarStyle: UIStatusBarStyle {
    get {
        return statusBarStyle
    }
}

private var statusBarStatus : Bool = false

override var prefersStatusBarHidden: Bool {
    get {
        return statusBarStatus
    }
}

然后我可以调用这样的函数:(这是我的示例之一，因此请忽略自定义函数)。

func sliderView(sliderView: SliderView, didSlideToPlace: CGFloat, within: CGFloat) {

    let val = (within - (didSlideToPlace - sliderView.upCent))/(within)
    print(val)
    //Where you would change the private variable for the color, for example.
    if val > 0.5 {
        statusBarStyle = .lightContent
    } else {
        statusBarStyle = .default
    }
    UIView.animate(withDuration: 0.5, animations: {
        sliderView.top.backgroundColor = UIColor.black.withAlphaComponent(val)
        self.coverLayer.alpha = val
        self.scroll.backgroundColor = colors.lightBlueMainColor.withAlphaComponent(val)
    }, completion: {
        value in
        //If you do not call setNeedsStatusBarAppearanceUpdate() in an animation block, the animation variable won't be called it seems.
        UIView.animate(withDuration: 0.4, animations: {

            self.animating = true

            //Where you set the status for the bar (your part of the solution)
            self.statusBarStatus = false

            //Then you call for the refresh
            self.setNeedsStatusBarAppearanceUpdate()
        })
    })
}

你最终不得不调整每个 View Controller ，但这似乎是你想要做的，所以希望它能有所帮助!