iOS background audio not playing

Question

I have an app that uses CoreBluetooth background modes. When a certain event happens I need to play an alarm sound. Everything works fine in the foreground and

Answer 1

By default, AVAudioPlayer uses the AVAudioSessionCategorySoloAmbient category, which is silenced by the ringer switch. The AVAudioSessionCategoryPlayback category is more appropriate for your situation, since it is not silenced by the switch, and will continue to play in the background:

NSURL *url = [NSURL fileURLWithPath:[[NSBundle mainBundle]
                                    pathForResource:soundName
                                    ofType:@"caf"]];

player = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:nil];
[player setCategory:AVAudioSessionCategoryPlayback error:nil];
player.numberOfLoops = -1;
[player setVolume:1.0];