When to reuse navigation controllers?

I'm trying to develop an app having a tab bar controller with 5 bar items. All of the items need navigation controllers. I just wanted to know whether it is possible to reuse the same naviga开发者_如何转开发tion controller for all the items. Are there any restrictions or things I need to keep in mind to do this?

Every tab in a UITabBarController should have its own UINavigationController, if you're in need of one that is. You push and pop UIViewControllers onto/off a stack and every UINavigationController has its own stack. Since the UIViewControllers from your other tabs have nothing to do with the navigation flow from the current tab, each tab should have its own UINavigationController.

I think I may have misinterpreted your question originally here... Navigation Controllers actually fine to re-use I think... I'd recommend release and creating a new on when the tab is changed if that makes sense within the application. You could give a reference to it in your appDelegate so it's easily accessible from each view controller.

Original reply follows in case I'm misinterpreting it still :S

The separation is entirely up to you, but for code clarity it's nice to have each viewcontroller separate. As a lot of the code will be found in your controller it's quite nice to separate out as much as possible. You can use the same controller, but change it's view property when each item is clicked, but it doesn't really save much and wil make for harder to maintain code...