App audio volume

Question

I need the user to control the device's media volume. I've seen many solutions using volume view or AVAudioPlayer, but I want to use the device volume buttons to set the app volume, like many apps have.

Thanks!

Answer 1

To use this functionality you need to set the audio session to playback. This is done with something like this:

AVAudioSession *session = [AVAudioSession sharedInstance];
[session setCategory:AVAudioSessionCategoryPlayback error:nil];

Answer 2

dumped in appdelegate

  - (BOOL)application:(UIApplication *)application
    didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
    {
        [[NSNotificationCenter defaultCenter]
         addObserver:self
         selector:@selector(volumeChanged:)
         name:@"AVSystemController_SystemVolumeDidChangeNotification"
         object:nil];
    }

    - (void)volumeChanged:(NSNotification *)notification
    {
        float volume =
        [[[notification userInfo]
          objectForKey:@"AVSystemController_AudioVolumeNotificationParameter"]
         floatValue];

        // Do stuff with volume
    }