Question

I’m trying to add some navigation controller in my app, it’s sth likes:

in my index page view controller, I try to initialize the navigation controller like this:

-(void)viewDidLoad{
    ...
    //allocate a navigation controller.
    myNavigationController = [[UINavigationController alloc]init];
    myNavigationController.delegate = self;
    myNavigationController.navigationBar.hidden = YES;
    [self.view addSubview:myNavigationController.view];

    [myNavigationController pushViewController:tabViewController animated:YES];
    [self presentModalViewController:myNavigationController animated:YES];
}

Here, index page view controller is the root view controller of my app, it’s just a common UIViewController here.

[myNavigationController pushViewController:tabViewController animated:YES];

The tabViewController here I’ve pushed into the navigation controller is a custom tabview controller which makes use of a container view to hold the tab button and also holds an navigation controller for tab switching.

The problem here is:

myNavigationController.navigationBar.hidden = YES;

since I’ve make the navigation bar invisible, it doesn’t show when my custom view controller shows, but when I’d like to switch to some other view controller with the navigation controller and I also want the navigation bar visible:

myNavigationController.navigationBar.hidden = NO;
MyViewController *toSwitchNC = [[MyViewController alloc]init];
[myNavigationController pushViewController:toSwitchNC animated:YES]; 

The navigation bar would never show any more. I’ve also tried to put:

self.navigationController.navigationBar.hidden = NO

in MyViewController’s viewDidLoad, ViewDidAppear or even in the navigation controller’s delegate method, it didn’t show the navigation bar neither.

So what’s wrong with it? Why I initialized the navigation bar to be invisible at first, it will never show again even I set the hidden flag to be false?

Answer 1

Okay, I’ve got this fixed by removing the navigation controller container in my index page view controller. This might be a stupid question, since apple’ve formally stated in the developer document that the navigation view controller should be place as root as possible in the view stack. Since IOS is a closed system, who knows WTH is going on under-beneath except Apple.