AVAudioPlayer closed while starting the app

When I start my app on iphone at that time my AVAudioPlayer gets closed. and I want that when I start my app in background AVAudioplayer should be on and when I close my app AVAudioPlayer star开发者_Go百科ted automatically. Why does this happen. can anyone tell me?

use following to activate sharedInstance of AudioPlayer while app is in background

[[AVAudioSession sharedInstance] setActive: YES error: nil];

Also for more code refer Play one instance of AVAudioPlayer in the background