NSURL *fileURL=[NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/start.m4v", [[NSBundle mainBundle] resourcePath]]];
MPMoviePlayerController *moviePlayerController=[[MPMoviePlayerController alloc]initWithContentURL:fileURL];
[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(moviePlaybackComplete:) name:MPMoviePlayerPlaybackDidFinishNotification object:moviePlayerController];
[moviePlayerController prepareToPlay];
[self.view addSubview:moviePlayerController.view];
moviePlayerController.fullscreen=YES;
[moviePlayerController play];
moviePlayerController.scalingMode=MPMovieScalingModeFill;
動作しません。常に白く、何も表示されません!何が問題なのですか?