改善需要UINavigationBar的UIViewControllers的可移植性

Question

We often try to reuse our view controllers, whether they get pushed to a navigation controller or are presented. However, things can get a little hairy when an explicit UINavigationBar is part of the view controller's function design.

If we just set the view controller's navigation item, pushing to a navigation controller works as expected, but presenting results in no navigation bar at all. On the other hand, if we explicitly add and configure a UINavigationBar to the view, presenting works fine, but pushing results in double navigation bars. While we could specify the parent navigation controller's navigation bar to be hidden for that view, it creates a clumsy animated transition when pushing or popping that view controller.

(In a perfect world, I would imagine that the navigationBar property would be managed by UIViewController instead of UINavigationController. Alas, that's not the case, so here I am.)

What are some of the best practices people here have found to maintain the portability of view controllers requiring a UINavigationBar?

Answer 1

I've handled this in one of two ways:

1. I fall back to asserting viewDidAppear: that self.navigationController is non-nil. Push the responsibility of providing a UINavigationController to wrap your view controller instance to clients of the class.

2. Alternatively, you can embed a UINavigationBar instance and manage it yourself, just remember to hide the possible navigation bar from your containing navigation controller in viewWillAppear: .