如何确定媒体播放器已停止在 ios 中播放

Question

我需要在应用程序中以幻灯片形式显示图像和视频。我将图像和视频链接保存在一个数组中，并确定哪个是视频，哪个是图像，并根据视频时间长度和每张图像 2 秒设置幻灯片放映时间，现在问题是当我开始幻灯片放映时视频来了就播放，我无法确定视频是否停止播放？

我正在使用 MPMediaplayer 并检查停靠点

      if (player.playbackState == MPMoviePlaybackStatePlaying)
      { //playing
      }
      if (player.playbackState == MPMoviePlaybackStateStopped)
      { //stopped
      }if (player.playbackState == MPMoviePlaybackStatePaused)
      { //paused
      }if (player.playbackState == MPMoviePlaybackStateInterrupted)
      { //interrupted
      }if (player.playbackState == MPMoviePlaybackStateSeekingForward)
      { //seeking forward
      }if (player.playbackState == MPMoviePlaybackStateSeekingBackward)
      { //seeking backward
      }

但当视频停止时，它一直会转到MPMoviePlaybackStatePaused 部分。谁能帮助我为什么在视频停止时它一直处于这种状态？或任何其他可以帮助我确定视频已停止播放的方法？

Answer 1

添加这个观察者

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(moviePlayerPlaybackStateDidChange:) name:MPMoviePlayerPlaybackStateDidChangeNotification object:nil];

查看 MPMoviePlaybackStatePlaying 的通知

- (void) moviePlayerPlaybackStateDidChange: (NSNotification *) notification {
     if (moviePlayer.playbackState == MPMoviePlaybackStateStopped) {
     }
}

Answer 2

像这样注册MPMoviePlayerPlaybackStateDidChangeNotification

[[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(MPMoviePlayerPlaybackStateDidChange:) 
                                                 name:MPMoviePlayerPlaybackStateDidChangeNotification 
                                               object:nil];

在通知处理程序方法中，检查实际状态 - 例如像这样：

- (void)MPMoviePlayerPlaybackStateDidChange:(NSNotification *)notification
{

  if (player.playbackState == MPMoviePlaybackStateStopped)
  { 
     //stopped playing

  } else if (player.playbackState == MPMoviePlaybackStatePlaying) {

    //is playing

  } else {

  }
}

要删除观察者，请使用此代码

[[NSNotificationCenter defaultCenter] removeObserver:self 
                                                name:MPMoviePlayerPlaybackDidFinishNotification
                                              object:nil];

请参阅MPMoviePlayerController_Class playback property 文档了解更多信息。