Ios 视频关闭时，将不会触发AnimationCoordinator的WillendFullScreen演示

您好，我有一个基于Xamarin MvvmCross框架的应用程序，它使用iOS中NSProject库的AVPlayerItem。每当视频播放关闭时，由于观察者在动画协调器的全屏演示结束时发出通知，应弹出测验。最常见的情况是，函数WillEndFullScreenPresentation被激发。但有时当我在暂停时滑动过快或关闭时，此函数会在调用视频播放之前启动。如何防止这种情况发生

private void SetVideoPlayer(VideoAsset video)
        {

            var player = new AVPlayer(new NSUrl(video.VideoUrl));
            ViewModel.WatchedVideoAssetCommand.Execute(video);
            aVPlayerViewController = new AVPlayerViewController();
            aVPlayerViewController.Player = player;
            aVPlayerViewController.Delegate = this;
            this.PresentViewController(aVPlayerViewController, true, () =>
            {
                aVPlayerViewController.Player?.Play();
            });
            //NotificationCenter.default.addObserver(self, selector: Selector(("playerDidFinishPlaying:")),
            //name: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: fourVideoPlayer.player.currentItem)
            
            NSNotificationCenter.DefaultCenter.AddObserver(AVPlayerItem.DidPlayToEndTimeNotification, (notify) => {
                notify.Dispose();
                aVPlayerViewController.DismissModalViewController(true);
            });

            NSNotificationCenter.DefaultCenter.AddObserver(AVPlayerItem.ItemFailedToPlayToEndTimeNotification, (notify) =>
            {
                notify.Dispose();
                aVPlayerViewController.DismissModalViewController(true);
            });
        }

        [Export("playerViewController:willEndFullScreenPresentationWithAnimationCoordinator:")]
        public void WillEndFullScreenPresentation(AVPlayerViewController playerViewController, IUIViewControllerTransitionCoordinator coordinator)
        {
            ViewModel.StartQuizForVideoAssetCommand.Execute(ViewModel.PlayingAsset);
        }

AVPlayer有一个属性：

但有时当我在暂停时滑动过快或关闭时，此函数会在调用视频播放之前启动

您可以在

WillEndFullScreenPresentation

方法中检查此状态，以确定是否需要退出全屏

示例代码如下：

[Export("playerViewController:willEndFullScreenPresentationWithAnimationCoordinator:")]
public void WillEndFullScreenPresentation(AVPlayerViewController playerViewController, IUIViewControllerTransitionCoordinator coordinator)
{
    if (aVPlayerViewController.Player.TimeControlStatus != AVFoundation.AVPlayerTimeControlStatus.Paused || aVPlayerViewController.Player.TimeControlStatus != AVFoundation.AVPlayerTimeControlStatus.WaitingToPlayAtSpecifiedRate)
    {
        ViewModel.StartQuizForVideoAssetCommand.Execute(ViewModel.PlayingAsset);
    }

}

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应用此修复后，没有注意到太多差异，但很少产生错误。事实上，很难重现这个错误。@t好的，如果回答有帮助，请不要忘记接受它作为答案（单击✔ 在这个答案的左上角）投票，它将帮助其他有类似问题的人。