iPhone-导航栏“后退”按钮项没有响应

Question

I have a fullscreen modalView called like this:

PreferencesController *nextWindow = [[[PreferencesController alloc] initWithNibName:@"Preferences" bundle:nil] autorelease];
UINavigationController* navController = [[[UINavigationController alloc] initWithRootViewController:nextWindow] autorelease];
[self presentModalViewController:navController animated:YES];

Then from this modalView I push another view :

    MyController *nextWindow = [[[MyController alloc] initWithNibName:@"tmp" bundle:nil] autorelease];
    [self.navigationController pushViewController:nextWindow animated:YES];

In this new controller, I have this viewDidLoad :

- (void)viewDidLoad {
    [super viewDidLoad];

    self.title = @"Borders";
    self.navigationController.navigationBarHidden = NO;
}

The leftBarButtonItem is not active, I mean touching it does not highlight it nor does it go back to the previous view.

My views are displayed fullScreen, with [[UIApplication sharedApplication] setStatusBarHidden:YES withAnimation:UIStatusBarAnimationNone]; called at the application initialisation.

The navigationBar frame is 0,0,320,44.
The navigationBar superview frame is 0,0,320,480.
The viewController view frame is 0,0,320,436.

I've tried to call in viewDidLoad self.navigationController.navigationBar.userInteractionEnabled = YES; and self.navigationItem.leftBarButtonItem.enabled = YES; without effect.

What happens?

My self.navigationController.navigationItem.backBarButtonItem is NIL. self.navigationController.navigationItem is not NIL

Answer 1

Whenever this sort of unresponsiveness happens to me, it is always because of framing issues. ie the superview of the NavigationController is smaller than the NavigationController's view. I know you say that everything is set to full screen, but I would verify that everything is actually full screen by turning "clipsSubviews" on for each view in the hierarchy.

Answer 2

I just had this issue, I'm not sure why this works, but instead of doing:

UIBarButtonItem *backButton =
[[[UIBarButtonItem alloc] initWithTitle:@"Back"
                                  style: UIBarButtonItemStyleBordered
                                 target:nil
                                 action:nil] autorelease];

self.navigationItem.leftBarButtonItem = backButton;

I replaced the second line with

 self.navigationController.navigationItem.leftBarButtonItem = backButton;

That works for me.

Answer 3

I found the solution. The problem was that the first view was called from the overlay, and not from the picker. Keeping a reference to the Picker into the overlay, and calling the view from it solves the problem:

From the overlay:

[self.picker presentModalViewController:navController animated:YES];

works

instead of:

[self presentModalViewController:navController animated:YES];