MPMoviePlayer错误的激活状态？(MPMoviePlayer wrong activation state?)

 我正在使用内置的MPMoviePlayerController播放视频。我在使用两个MPMoviePlayerControllers时遇到了问题（请注意，在同一时间没有播放两个视频）。 我可以在第一个控制器上播放尽可能多的视频，在完成后处理它，然后分配另一个MPMoviePlayerController。 一旦我在第二个控制器上设置controlStyle，我就会得到一个SIGABRT 
 
 因未捕获的异常'NSInternalInconsistencyException'而终止应用程序，原因：'电影播放器​​的激活状态错误（1） 
 
 我在网上搜索过，在堆栈溢出时发现了类似的问题。 那家伙说他忘了删除播放完成的通知。 我相信我已经使用[[NSNotificationCenter defaultCenter] removeObserver：self]正确完成了这项工作。 
 
 我还是得到了崩溃。 相当令人沮丧！ 
 
 我不明白为什么只要它们不同时播放就不可能使用两个控制器。 我宁愿不必深入研究AVPlayer的内容，只是为了让视频正常运行。 
 
 谢谢！ 
 
 编辑：注释掉controlStyle分配仍然会导致崩溃。 下面是已发布的callstack，以及该类中的一些重要方法。 
 
- (void) makePlayer;
{
[player.view removeFromSuperview];
[player release];
player = [MPMoviePlayerController new];
player.view.frame = self.bounds;
player.view.hidden = YES;
player.controlStyle = MPMovieControlStyleNone;
player.scalingMode = MPMovieScalingModeNone;
[self addSubview: player.view];
}

- (void) dealloc;
{
[[NSNotificationCenter defaultCenter] removeObserver: self];
[player.view removeFromSuperview];
[player release];
[super dealloc];
}

- (void) setMovieByName: (NSString *) name;
{
[self makePlayer];
player.shouldAutoplay = NO;
[player setContentURL: [NSURL fileURLWithPath: [[NSBundle mainBundle] pathForResource: name ofType: @"mov"]]];
[player stop];
[player prepareToPlay];
[[NSNotificationCenter defaultCenter] removeObserver: self];
[[NSNotificationCenter defaultCenter] addObserver: self selector:@selector(movieDimensionsKnown:) name:MPMovieNaturalSizeAvailableNotification object: player];
[[NSNotificationCenter defaultCenter] addObserver: self selector:@selector(playbackStateChanged:) name:MPMoviePlayerPlaybackStateDidChangeNotification object: player];
[[NSNotificationCenter defaultCenter] addObserver: self selector:@selector(playbackFinished:) name:MPMoviePlayerPlaybackDidFinishNotification object: player];
}

- (void) playbackFinished: (NSNotification *) n
{   
player.view.hidden = YES;
if ([delegate respondsToSelector: @selector(moviePlayerImageViewPlaybackDidFinish:)])
    [delegate moviePlayerImageViewPlaybackDidFinish: self];
}

I am using the built in MPMoviePlayerController for playing videos.I've run in to a problem when using two MPMoviePlayerControllers (Note that no two videos are played at the exact same time). I can play as many videos as I want on the first controller, dispose of it when I'm done, and then allocate another MPMoviePlayerController. As soon as I set the controlStyle on the second controller, I get a SIGABRT with 
 
Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'movie player has wrong activation state (1)
 
I have searched online and found a similar problem on stack overflow. The guy said he had forgotten to remove the playback finished notification. I believe I have done this properly using [[NSNotificationCenter defaultCenter] removeObserver: self];
 
I still get the crash. Rather frustrating!
 
I don't see why it wouldn't be possible to use two controllers as long as they aren't being played at the same time. I'd rather not have to dig in to AVPlayer stuff just to get videos working.
 
Thanks!
 
Edit: Commenting out the controlStyle assignment still results in a crash. Below is the posted callstack, along with a few important methods from the class.
 
- (void) makePlayer;
{
[player.view removeFromSuperview];
[player release];
player = [MPMoviePlayerController new];
player.view.frame = self.bounds;
player.view.hidden = YES;
player.controlStyle = MPMovieControlStyleNone;
player.scalingMode = MPMovieScalingModeNone;
[self addSubview: player.view];
}

- (void) dealloc;
{
[[NSNotificationCenter defaultCenter] removeObserver: self];
[player.view removeFromSuperview];
[player release];
[super dealloc];
}

- (void) setMovieByName: (NSString *) name;
{
[self makePlayer];
player.shouldAutoplay = NO;
[player setContentURL: [NSURL fileURLWithPath: [[NSBundle mainBundle] pathForResource: name ofType: @"mov"]]];
[player stop];
[player prepareToPlay];
[[NSNotificationCenter defaultCenter] removeObserver: self];
[[NSNotificationCenter defaultCenter] addObserver: self selector:@selector(movieDimensionsKnown:) name:MPMovieNaturalSizeAvailableNotification object: player];
[[NSNotificationCenter defaultCenter] addObserver: self selector:@selector(playbackStateChanged:) name:MPMoviePlayerPlaybackStateDidChangeNotification object: player];
[[NSNotificationCenter defaultCenter] addObserver: self selector:@selector(playbackFinished:) name:MPMoviePlayerPlaybackDidFinishNotification object: player];
}

- (void) playbackFinished: (NSNotification *) n
{   
player.view.hidden = YES;
if ([delegate respondsToSelector: @selector(moviePlayerImageViewPlaybackDidFinish:)])
    [delegate moviePlayerImageViewPlaybackDidFinish: self];
}

原文：https://stackoverflow.com/questions/6783596