Question

I am probably missing the obvious here, I am in a viewController that has been pushed onto a UINavigationController stack when the user selects a button on the “Main” screen.

What I am trying to do is get to a point where I can access the UIBarButtonItem for the back button (Shown on the image as “Main”) and call setBackButtonBackgroundImage:forState:barMetrics: to customize the button.

What I am confused about is do I need to do this from each UIViewController that is pushed on, or is it something that I need to do just once on the UINavigationController itself?

I thought I might be able to access what I wanted from the pushed controller using:

UINavigationItem *navItem = [self navigationItem];

but think I am getting mixed up with the way things are setup.

Answer 1

The one that can customize the back button is the controller that disappears, say, you have controller A that pushes into controller B. The back button that you see on controller B is A’s back button.

If you want to customize ALL buttons in your app, you could subclass UINavigationController, make sure you use it and not a regular UINavigationController and on the pushViewController:animated method you could do this:

controller.navigationItem.backBarButtonItem = ...; // Your custom back button
[super pushViewController...];

EDIT
You cannot access the default back button, you can only create a new one to replace it.