iphone - Presenting modal view occasionally hides the navigation bar

Question

I've come across this twice now.

Sometimes using the following line of code:

[self.navigationController presentModalViewController:aViewController animated:YES];

displays the view, but the navigation bar is then hidden.

I can write:

[self.navigationController setNavigationBarHidden:NO];

to my hearts content, everywhere I can think of with no effect.

Has anyone ran into this?

Am I doing something silly?

Answer 1

No, I ran into this as well. The problem is that when you present a modal view controller with a UIViewController based class, it does not extend the calling navigation controller's nav bar onto the modal. The modal view covers the entire screen. What I ended up doing to solve the problem was to create a UINavigationController and push the UIViewController based class onto it, and then do presentModalViewController to the navigation controller's instance.

like:

UIViewController *vc = [[UIViewController alloc] init];
UINavigationController *cntrol = [[UINavigationController alloc] initWithRootViewController:vc];
[self presentModalViewController:cntrol animated:YES];
[cntrol release];

That allowed me to have a nav bar at the top.

I am not sure if that will help in your particular case, the only other thing I would suggest is to replicate the behavior of the modal with a UIAnimation that stops 44px below the top of the phone. That would keep the original navigation bar visible.