For TabBarItem associated NavigationController.xib interface does not show the problem (newbie)

There is a main interface TabBarController, I've set up a TabBarItem's Class of "InputNavigationController", then NIB Name is "InputViewController", Title is "Input", then there is a InputViewController.xib, these are a good set directly on the interface , InputNavigationController.h and InputNavigationController.m Lane did not write any code (InputNavigationController is a class that inherits from UINavigationController), I want the first one interface Click TabBarItem interface shows InputViewController.xib this interface, but better now Like this screen does not show up, because I InputViewController only put a Navigation Controller, but in the Navigation on top of a button, so if the correct operation of the Navigation Controller should be displayed on the button, now runs only shows a Navigation Controller , nothing above, there is because I am in the Title is set above the "input" but the latter did not show up in Navigation,
Please help me solve what are the reasons
Reply:
file's owner has no right to change
Reply:
I have encountered similar problems in the simulator is not the display interface