为什么不可能多次使用MPMoviePlayerController?
在MonoTouch中,我们遇到了这个电影播放器示例的问题,因为它只播放一次视频,但不会再播放一次。为什么不可能多次使用MPMoviePlayerController?
我在问这个问题发表了一个答案,因为它已经击中了各种各样的人。
MPMoviePlayerController是引擎盖下的单身人士。如果您没有正确释放'd(ObjC)或Dispose()'d(MonoTouch),并且您创建了第二个实例,它将不会播放或仅播放音频。
此外,如果您订阅MPMoviePlayerScalingModeDidChangeNotification或MPMoviePlayerPlaybackDidFinishNotification或MPMoviePlayerContentPreloadDidFinishNotification,予以警告,张贴NSNotification需要到的MPMoviePlayerController的引用一样,所以,如果你把它周围,你就会有一个参考的球员。尽管Mono的垃圾收集器最终会启动,但这是一个需要确定性终止的情况(当GC决定执行一个收集时,您希望参考消失现在,而不是消失)。
这就是为什么你要调用控制器上的Dispose()方法和通知上的Dispose()方法。
例如:
// Deterministic termination, do not wait for the GC
if (moviePlayer != null){
moviePlayer.Dispose()
moviePlayer = null;
}
如果您正在收听的通知,调用Dispose在年底的通知处理程序,以释放它让你的MPMoviePlayerController例如参考:
var center = NSNotificationCenter.DefaultCenter;
center.AddObserver (
"MPMoviePlayerPlaybackDidFinishNotification"),
(notify) => { Console.WriteLine ("Done!"); notify.Dispose(); });
秘密在endPlay中设置:moviePlayer.initialPlaybackTime = -1;在释放它之前,请使用 。 试试看: :)
-(void)playMovie:(NSString *)urlString{
movieURL = [NSURL URLWithString:urlString];
moviePlayer = [[MPMoviePlayerController alloc] initWithContentURL:movieURL];
moviePlayer.initialPlaybackTime = 0;
//Register to receive a notification when the movie has finished playing.
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(endPlay:)
name:MPMoviePlayerPlaybackDidFinishNotification
object:moviePlayer];
moviePlayer.scalingMode = MPMovieScalingModeAspectFit;
moviePlayer.movieControlMode = MPMovieControlModeDefault;
moviePlayer.backgroundColor = [UIColor blackColor];
[moviePlayer play];
}
-(void)endPlay: (NSNotification*)notification{
[[NSNotificationCenter defaultCenter] removeObserver:self name:MPMoviePlayerPlaybackDidFinishNotification object:moviePlayer];
moviePlayer.initialPlaybackTime = -1;
[moviePlayer stop];
[moviePlayer release];
}
无法看到你的代码尼尔和我没有编辑权限,所以这里要再次重申:
与设定端隙秘密规定: moviePlayer.initialPlaybackTime = -1;在发布之前。试试看:) :)
-(void)playMovie:(NSString *)urlString{ movieURL = [NSURL URLWithString:urlString];
moviePlayer = [[MPMoviePlayerController alloc] initWithContentURL:movieURL];
moviePlayer.initialPlaybackTime = 0;
//Register to receive a notification when the movie has finished playing.
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(endPlay:) name:MPMoviePlayerPlaybackDidFinishNotification object:moviePlayer];
moviePlayer.scalingMode = MPMovieScalingModeAspectFit;
moviePlayer.movieControlMode = MPMovieControlModeDefault;
moviePlayer.backgroundColor = [UIColor blackColor];
[moviePlayer play];
}
-(void)endPlay: (NSNotification*)notification{
[[NSNotificationCenter defaultCenter] removeObserver:self name:MPMoviePlayerPlaybackDidFinishNotification object:moviePlayer];
moviePlayer.initialPlaybackTime = -1;
[moviePlayer stop];
[moviePlayer release];
}