MPMusicPlayerController function stop causes crash
<p>I use codes below to play ipod audio library.</p>

<pre><code>if( musicPlayer==nil)
{

    MPMusicPlayerController* playa=[[MPMusicPlayerController alloc]init];

    musicPlayer=playa;
    [ playa release];
}

 musicPlayer = [MPMusicPlayerController applicationMusicPlayer];
 [musicPlayer setShuffleMode: MPMusicShuffleModeOff];
 [musicPlayer setRepeatMode: MPMusicRepeatModeNone];
 [musicPlayer setQueueWithItemCollection: userMediaItemCollection];
 [musicPlayer play];
</code></pre>

<p>when I pressed a button, it will fire function below to stop playing</p>

<pre><code>-(void)stopMusicPlayer;
{

   if (playbackState == MPMusicPlaybackStatePlaying) {
        [ musicPlayer stop];
   }    


}
</code></pre>

<p>but it crash and exit.</p>

<p>Welcome any comment</p>

<p>Thanks
interdev</p>
