Question

I need a custom leftBarButtonItem on my navigation bar because I need to perform a function in the view controller when the view is popped. I would like to have the back button have the correct title (of the view controller below). So two questions:

1) Can I get the title of the standard backBarButton item somehow, so that I can manually set my custom button’s title?

or

2) Is there another hook/event that I can use that is only called when the user pops the view?

Re 2: I found one solution using:

NSArray *viewControllerArray = [self.navigationController viewControllers]; 
int parentViewControllerIndex = [viewControllerArray count] - 2;

But this array is (null) for me.

PS I’m using Three20.

Answer 1

There’s a UIViewController function which gets triggered when the view controller disappears from the screen:

- (void)viewWillDisappear:(BOOL)animated {
   [super viewWillDisappear:animated];

   .....
}