You can create an ivar in class B that refer to class A instance. Set that ivar, when class B instance is created. So, you can call the methods in class A by using that instance, without searching through the view controllers array.
Besides, you can also change the title before class B is pushed. You should not refer to the navigation controller's parent. You should refer to the current view controller's parent. self.parentViewController.navigationItem.title = @"New Title" That's if the parentViewController is not nil. I never used this property. Jesse Armand ---------------------------------------- (http://jessearmand.com) On Sun, Sep 20, 2009 at 3:34 AM, Alex Reynolds <alexpreyno...@gmail.com> wrote: > I have a view hierarchy managed with UINavigationController, of the form A > -> B, where A and B are UIViewController subclasses. > > When I am in the B view, I have a backBarButtonItem in the navigation bar > that will pop the application back to the A view, when selected. > > The title of the backBarButtonItem was initially set in A, just before I > pushed the B view onto the navigation stack. > > Assuming I am in B and I would like to change the title of the > backBarButtonItem, what is the best way to accomplish this? > > Currently, I have a method in A that sets the title property value: > > - (void) setBackBarButtonItemTitle:(NSString *)newTitle { > self.navigationItem.backBarButtonItem.title = newTitle; > } > > When in B, I call -viewControllers to get the array of view controllers, > referencing the second to last element to call A's > -setBackBarButtonItemTitle: > > NSArray *viewControllerArray = [self.navigationController > viewControllers]; > int parentViewControllerIndex = [viewControllerArray count] - 2; > [[viewControllerArray objectAtIndex:parentViewControllerIndex] > setBackBarButtonItemTitle:@"New Title"]; > > This approach is clunky but it seems to work correctly. > > However, I don't know why the following does not work, when called within B: > > [(A *)(self.navigationController.parentViewController) > setBackBarButtonItemTitle:@"New Title"]; > > In fact, calling any parent view methods using the parentViewController > property does not work. > > Why does this second approach (using the parentViewController property) fail > to work? Am I not using this property correctly? > > Thanks, > Alex > _______________________________________________ > > Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > > Please do not post admin requests or moderator comments to the list. > Contact the moderators at cocoa-dev-admins(at)lists.apple.com > > Help/Unsubscribe/Update your Subscription: > http://lists.apple.com/mailman/options/cocoa-dev/mnemonic.fx%40gmail.com > > This email sent to mnemonic...@gmail.com > _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
