How do I make my app work with the media control buttons on lock screen?

Question

In recent iOS versions apps have some kind of access to the media control buttons on the lock screen, like the Play/Pause button:

It looks like the buttons are supposed to work with the MPMusicPlayerController class, is that right? Is there a way to get the “raw” events from the buttons? Because the music player only seems to offer an API to supply a bunch of MPMediaItems. What if my app is for example a radio that needs to handle the buttons differently?

Answer 1

After a bit more searching I have found this related question that makes things clear. The music player controller class is not really the right track, the trick is to subscribe for remote events in your controller:

- (void) viewDidAppear: (BOOL) animated
{
    [super viewDidAppear:animated];
    [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
    [self becomeFirstResponder];
}

- (BOOL) canBecomeFirstResponder
{
    return YES;
}

- (void) remoteControlReceivedWithEvent: (UIEvent*) event
{
    // see [event subtype] for details
}