Updating the navigation bar after a change using UIAppearance

Question

I am currently setting up the background image of the navigation bar of an iOS application using the UIAppearance proxy. There is a button for switching between two different modes that trigger a notification. This notification will change the background to another image using the proxy again. My problem is that this change only becomes visible when I switch to another controller and I return to it. I cannot force update the navigation bar in the controller.

I tried this in my MainTabBarController:

- (void) onAppChangedMode: (NSNotification*)notif { APP_MODE mode = (APP_MODE) [[notif object] integerValue]; // change navigation bar appearance [[UILabel appearance] setHighlightedTextColor:[UIColor redColor]]; [[UINavigationBar appearance] setBackgroundImage:[UIImage imageNamed:(mode == 0 ? @"navbar.png" : @"navbar2.png")] forBarMetrics:UIBarMetricsDefault]; // trying to update for (UIViewController* vc in self.viewControllers) { [vc.navigationController.navigationBar setNeedsDisplay]; } } 

but nothing ... it does not work. Any idea how to achieve it?

Thanks!

Answer 1

Try this code to change the background image for the current navigation bar only :

 [self.navigationController.navigationBar setBackgroundImage:image forBarMetrics:UIBarMetricsDefault]; 

Use the above code after changing the UIAppearance. This will change the navigation bar of the current controller. Navigation bars for other controllers will be handled by changing the UIAppearance.

Answer 2

Just remove the views from the windows and add them again:

 for (UIWindow *window in [UIApplication sharedApplication].windows) { for (UIView *view in window.subviews) { [view removeFromSuperview]; [window addSubview:view]; } } 

Answer 3

I just have the same problem, this code will help you:

 - (IBAction)btnTouched:(id)sender { [[UADSwitch appearance]setOnTintColor:[UIColor redColor]]; // Present a temp UIViewController UIViewController *vc = [[UIViewController alloc]init]; [self presentViewController:vc animated:NO completion:nil];//"self" is an instance of UIViewController [vc dismissViewControllerAnimated:NO completion:nil]; }