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：

 

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。

 

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];
}