I'm using a storyboard and I'm trying to hide a top bar of my main navigation controller when a certain button is pressed (or function is called). I know I have to initialize an object referring to a navigation controller from a storyboard (using identifiers), but when I send the setNavigationBarHidden message to this newly created object nothing really happens on screen.
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
UINavigationController *navController = (UINavigationController*) [storyboard instantiateViewControllerWithIdentifier:@"MyNavController"];
[navController setNavigationBarHidden:YES animated:YES];
Finally solved it. You should always hide navigation bar only through viewController.
In my question above I instantiated a whole new navigationController which didn't point at the real navController on the screen. You can obtain the "real" one through the view controller like this:
[viewController.navigationController setNavigationBarHidden:YES animated:YES];