app could not be continue with next song in background

I've created a simple music App for iPad using AVAudioPlayer. But the problem is that when I pressed home button it only plays current song in background. The application could not continue with 开发者_如何学编程next song in background.

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this works for me

    here musicPlayer is MPMusicPlayerController 

    [self setMusicPlayer: [MPMusicPlayerController applicationMusicPlayer]];

    // By default, an application music player takes on the shuffle and repeat modes

    //      of the built-in iPod app. Here they are both turned off.

    [musicPlayer setShuffleMode: MPMusicShuffleModeOff];

    [musicPlayer setRepeatMode: MPMusicRepeatModeNone];