iOS 视频播放(一) MPMoviePlayerViewController、避免在后台销毁

转自:http://blog.csdn.net/xueer8835/article/details/22286629

#import <MediaPlayer/MediaPlayer.h>MediaPlayer.framework。MPMoviePlayerViewController：打开网络视频：-(void)openmovie{    MPMoviePlayerViewController *movie = [[MPMoviePlayerViewControlleralloc]initWithContentURL:[NSURLURLWithString:@"视频网络地址"]];        [movie.moviePlayer prepareToPlay];    [self presentMoviePlayerViewControllerAnimated:movie];    [movie.moviePlayersetControlStyle:MPMovieControlStyleFullscreen];        [movie.viewsetBackgroundColor:[UIColorclearColor]];        [movie.view setFrame:self.view.bounds];    [[NSNotificationCenterdefaultCenter]addObserver:self                                                  selector:@selector(movieFinishedCallback:)                                                      name:MPMoviePlayerPlaybackDidFinishNotification                                                    object:movie.moviePlayer];}-(void)movieFinishedCallback:(NSNotification*)notify{        // 视频播放完或者在presentMoviePlayerViewControllerAnimated下的Done按钮被点击响应的通知。        MPMoviePlayerController* theMovie = [notifyobject];        [[NSNotificationCenterdefaultCenter]removeObserver:self                                                         name:MPMoviePlayerPlaybackDidFinishNotification                                                       object:theMovie];        [selfdismissMoviePlayerViewControllerAnimated];    }打开本地视频：-(void)openmovie{     NSString *url = [[NSBundlemainBundle]pathForResource:@"IMG_0322"ofType:@"mp4"];    MPMoviePlayerViewController *playerViewController  = [[MPMoviePlayerViewControlleralloc]initWithContentURL:[NSURLfileURLWithPath:url]];    [[NSNotificationCenterdefaultCenter]addObserver:selfselector:@selector(movieFinishedCallback:)                                                name:MPMoviePlayerPlaybackDidFinishNotification                                              object:[playerViewControllermoviePlayer]];    [self.view addSubview:playerViewController.view];        MPMoviePlayerController *player = [playerViewControllermoviePlayer];    [playerplay];    }- (void) movieFinishedCallback:(NSNotification*) aNotification {   MPMoviePlayerController *player = [aNotificationobject];    [[NSNotificationCenterdefaultCenter]removeObserver:selfname:MPMoviePlayerPlaybackDidFinishNotificationobject:player];    [playerstop];    [player.viewremoveFromSuperview];   }

避免MPMoviePlayerViewController播放完毕后自动dismiss，进入后台自动dismiss

MPMoviePlayerViewController已经实现了一些通知的监听并对MPMoviePlayerController实现了一些控制，比如：

 

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1. 监听UIApplicationDidEnterBackgroundNotification通知，调用[movieplayer stop],播放器停止。

2. 监听MPMoviePlayerPlaybackDidFinishNotification（调用stop方法或视频播放结束时发送通知）通知，调用dismiss方法移除自身。

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需求1：app中一个课程包含若干个章节，所以每次播放完一个章节后要求直接加载播放下一个课程。

遇到问题：由于MPMoviePlayerViewController监听了MPMoviePlayerPlaybackDidFinishNotification通知，当一个视频播放完毕，它会在监听方法中　　　　　　　调用dismissMoviePlayerViewControllerAnimated方法，播放器视图就直接移除了。

解决方法：

// self为MPMoviePlayerViewController的一个实例对象。
       [[NSNotificationCenter defaultCenter] removeObserver:self                                                        name:MPMoviePlayerPlaybackDidFinishNotification                                                      object:nil];

 

需求2: app进入后台时播放器暂停，回到应用时继续播放

遇到问题：由于MPMoviePlayerViewController监听了UIApplicationDidEnterBackgroundNotification通知，当进入后台时，调用stop方法，随后接　　　　　　收到MPMoviePlayerPlaybackDidFinishNotification通知，调用dismiss方法移除自身视图。

解决方法：移除MPMoviePlayerViewController对UIApplicationDidEnterBackgroundNotification和MPMoviePlayerPlaybackDidFinishNotification　　　　　　通知的监听，并实现自己的监听方法

// UIApplicationDidEnterBackgroundNotification通知
- (void)appEnterBackground:(NSNotification*)notice{
　　// 进入后台时记录当前播放时间    overlay_flags.playTimeWhenEnterBackground = _player.currentPlaybackTime;    [_player pause];}
// UIApplicationWillEnterForegroundNotification通知
- (void)appEnterForeground:(NSNotification*)notice
{
　　// 设置播放速率为正常速度，设置当前播放时间为进入后台时的时间
    [_player setCurrentPlaybackRate:1.0];
    [_player setCurrentPlaybackTime:overlay_flags.playTimeWhenEnterBackground];
}