Iphone application with audio player

I have added music files in application's document folder and I am playing that music from AVAudioPlayer. How can I get Its title , album name and artist name.

I used MPmediaPlayer to access ipod library . but now I want to make my custom player. Is there any need to use mpmediaplayer in this type of app.I already get the albumtitle and artwork image of ipod songs

I am trying to get it like

NSError *activationError = nil;     
[[AVAudioSession sharedInstance] setActive: YES error: &activationError];

    // Instantiates the AVAudioPlayer object, initializing it with the sound    AVAudioPlaye开发者_运维技巧r *newPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL: soundFileURL error: nil];  self.appSoundPlayer
= newPlayer;

    musicPlayer = [MPMusicPlayerController applicationMusicPlayer];
    MPMediaItem *item = musicPlayer.nowPlayingItem ;

    nowPlayingLabel.text = [item valueForProperty:MPMediaItemPropertyTitle];
    NSLog(@"title %@",[item valueForProperty:MPMediaItemPropertyTitle]);    [newPlayer release];        // "Preparing to play" attaches to the audio hardware and ensures that playback     //      starts quickly when the user taps Play  [appSoundPlayer prepareToPlay];     [appSoundPlayer setVolume: 1.0];    [appSoundPlayer setDelegate: self];

    [appSoundPlayer currentTime];

title is returning (null)

Please help..