MPVolumeView AirPlay button not showing up

Using MPVolumeView I wanted to create an AirPlay output button for the app's audio.

MPVolumeView *volumeView = [ [MPVolumeView alloc] initWithFrame:CGRectMake(20, 20, 220, 20)];
    [volumeView setShowsVolumeSlider:NO];
    [volumeView setShowsRouteButton:YES];
    [volumeView sizeToFit];
    [self.view addSubview:volumeView];
    [volumeView release];

Errors / issues none but it doesn't show up, any ideas?
Thanks!

instead of init, send it initWithFrame:(CGRect) message. It seems like the view is there, it just has a frame of (0,0,0,0)

Here's the code:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Override point for customization after application launch.
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    ViewController *vc = [[ViewController alloc] init];
    [vc.view setBackgroundColor:[UIColor redColor]];
    MPVolumeView *volumeView = [[MPVolumeView alloc] initWithFrame:CGRectMake(20, 20, 200, 50)];
    [volumeView setShowsVolumeSlider:YES];
    [volumeView setShowsRouteButton:YES];
    [volumeView sizeToFit];
    [vc.view addSubview:volumeView];
    UILabel *testLabel = [[UILabel alloc] initWithFrame:CGRectMake(50, 50, 200, 50)];
    testLabel.text = @"TESTING";
    [vc.view addSubview:testLabel];
    [self.window setRootViewController:vc];
    [self.window makeKeyAndVisible];
    [vc viewDidLoad];
    return YES;
}

It works when testing on device: