Audio playing while app in background iOS

Question

I have an app mostly based around Core Bluetooth. When something specific happens, the app is woken up using Core Bluetooth background modes and it fires off an alarm, however I

Answer 1

You need to enable your app to handle audiosession interruptions (and ended interruptions) while in the background. Apps handle audio interruptions through notification center:

1. First, register your app with the notification center:

   - (void) registerForMediaPlayerNotifications {
   
       [notificationCenter addObserver : self
                               selector: @selector (handle_iPodLibraryChanged:)
                                   name: MPMediaLibraryDidChangeNotification
                                 object: musicPlayer];
   
       [[MPMediaLibrary defaultMediaLibrary] beginGeneratingLibraryChangeNotifications];
   
   }
   

2. Now save player state when interruption begins:

   - (void) audioPlayerBeginInterruption: player {
   
       NSLog (@"Interrupted. The system has paused audio playback.");
   
       if (playing) {
           playing = NO;
           interruptedOnPlayback = YES;
       }
   }
   

3. And reactivate audio session and resume playback when interruption ends:

   -(void) audioPlayerEndInterruption: player {
   
       NSLog (@"Interruption ended. Resuming audio playback.");
   
       [[AVAudioSession sharedInstance] setActive: YES error: nil];
   
       if (interruptedOnPlayback) {
           [appSoundPlayer prepareToPlay];
           [appSoundPlayer play];
           playing = YES;
           interruptedOnPlayback = NO;
       }
   }
   

Here's Apple's sample code with full implementation of what you're trying to achieve:

https://developer.apple.com/library/ios/samplecode/AddMusic/Introduction/Intro.html#//apple_ref/doc/uid/DTS40008845