iPhone Tab Bar Controller and Navigation Controller in outside file

I have an app which contains

exampleTabAppDelegate (.h and .m files)

MainWindow.xib

In MainWindow.xib, I have the following structure of my objects

Tab Bar Controller - has outlet and is set as rootViewController

Tab Bar

First View Controller - type UIViewController

Navigation Controller - type UINavigationController

View Controller

Also I have a NavigationController class which extends class UINavigationController (.h and .m files named NavigationController)

And for this class I have NIB file named NavigationController.xib.

So next, if I set property Class of Navigation Controller to NavigationController it's works and I get Log message which nested in NavigationController.m method viewDidLoad

But I also have NIB file for my NavigationController and it has its own NavBar but I don't see it.

When I 开发者_StackOverflow社区try to set property NIB Name of Navigation Controller to NavigationController, I think it should load my NIB file, but I get an exception and nothing is written to the log/console.

What do i need to do?

I want to have MainWindow.xib file with structure but design of navigation controller view set one another file.

Help. How can i do it?