обновить данные после перехода на передний план

После изменения настроек по умолчанию я хотел бы обновить данные myViewController, когда я выхожу на передний план в AppDelegate. Я делаю

AppDelegate .m

- (void)applicationDidFinishLaunching:(UIApplication *)application
{
    [window addSubview:[navigationController view]];
    NSLog(@"APPLICATION DID FINISH LAUNCHING");
    // listen for changes to our preferences when the Settings app does so,
    // when we are resumed from the backround, this will give us a chance to update our UI
    //
    [[NSNotificationCenter defaultCenter] addObserver:self
                                       selector:@selector(defaultsChanged:)
                                           name:NSUserDefaultsDidChangeNotification
                                         object:nil];
}

- (void)applicationWillEnterForeground:(UIApplication *)application
{
    /*
     Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
     */
    NSLog(@"APPLICATION WILL ENTER BACKGROUND");
    [myViewController viewDidLoad];
}

myViewController.m

- (void)viewDidLoad
{
    NSLog(@"VIEW DID LOAD IN MY VIEW CONTROLLER");
    // watch when the app has finished launching so we can update our preference settings and apply them to the UI
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(updateSettings:) 
                                        name:UIApplicationDidFinishLaunchingNotification object:nil];
}

- (void)updateSettings:(NSNotification *)notif
{
    myLabel.text = @"data has just been modified";
}

Однако здесь вообще ничего не изменилось.