在 iOS 14 上的一半屏幕上呈现 UIViewController

Posted 2023-02-23

【中文标题】在 iOS 14 上的一半屏幕上呈现 UIViewController

【英文标题】：Presenting UIViewController on half of screen on iOS 14

【发布时间】：2020-11-18 10:17:55

【问题描述】：

我一直在使用下面的代码sn-p来实现只在一半屏幕上呈现视图控制器的效果：

func showPlayerView() 
    let controller = storyboard!.instantiateViewController(withIdentifier: "playerViewController") as! PlayerViewController
    controller.player = self.player
    controller.providesPresentationContextTransitionStyle = true
    controller.definesPresentationContext = true
    controller.transitioningDelegate = self
    
    self.present(controller, animated: true, completion: nil)


extension ViewController : UIViewControllerTransitioningDelegate

    func presentationController(forPresented presented: UIViewController, presenting: UIViewController?, source: UIViewController) -> UIPresentationController? 
        if presented is PlayerViewController 
            return HalfSizePresentationController(presentedViewController: presented, presenting: presenting)
        
        return nil
    
    
    func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? 
        return animator
    
    func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? 
        return animator
    


class HalfSizePresentationController : UIPresentationController 
    override var frameOfPresentedViewInContainerView: CGRect
    
        get 
            let height: CGFloat = 200
            return CGRect(x: 0, y: UIScreen.main.bounds.height - height, width: UIScreen.main.bounds.width, height: 200)
        
    

这曾经在 tvOS 13 上工作，但现在从 tvOS 14 开始，我得到的是：

知道如何在 ios 14 上实现这一点吗？

【参考方案1】：

显然问题在于 tvOS 11 将默认过渡样式设置为与以前不同的样式。

我可以通过添加以下行来解决此问题：

controller.modalPresentationStyle = .custom

就在致电self.present(controller, animated: true, completion: nil)之前。

但是，这引入了一个新问题，导致原始 ViewController 在动画结束后消失，如下所述：Presented view controller disappears after animation using custom UIViewController animations

最终通过在我的UIPresentationController 中添加以下几行来解决它：

override func dismissalTransitionDidEnd(_ completed: Bool) 
    if let window = UIApplication.shared.keyWindow 
        if let viewController = window.rootViewController 
            window.addSubview(viewController.view)