视频关闭时不会触发 willEndFullScreenPresentationWithAnimationCoordinator

Question

您好，我有一个基于 Xamarin MvvmCross 框架的应用程序，它使用来自 iOS 的 NSOject 库的 AVPlayerItem。每当视频播放关闭时，由于观察者通知动画协调器的全屏演示结束时，应弹出测验。最常见的是，函数 WillEndFullScreenPresentation 被触发。但有时当我在暂停期间滑动过快或关闭时，会在调用视频播放之前触发此函数。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);
        }

Answer 1

AVPlayer有一个AVPlayerTimeControlStatus属性：

但有时当我在暂停期间滑动过快或关闭时，会在调用视频播放之前触发此函数。

您可以在WillEndFullScreenPresentation方法中查看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);
    }

}