viewDidAppear called twice in iOS5

Question

I'm developing an app with an UINavigatorController. I am using the method viewDidAppear in the second pushed viewController to find information in an external server.

Well. While in iOS5 worked fine at the beginning, I realized that viewDidAppear was not being called in iOS4.3 so I put this code in the root:

- (void)navigationController:(UINavigationController *)navigationController 
       didShowViewController:(UIViewController *)viewController animated:(BOOL)animated 
{
    [viewController viewDidAppear:animated];
}

Thereafter, the app started to work properly in iOS4.3. However, in iOS5 didn't because it's calling twice viewDidAppear (the one which was being called at first and the one from the navigationController:didShowViewController:animated:)

What should I do to have only called once viewDidAppear?

Thank you very much

Answer 1

The only real solution I see (or rather workaround for iOS 4.x) if you set some kind of state in your viewWillAppear-call and check whether it's been set or not in subsequent calls, e.g.

-(void)viewWillAppear:(BOOL)animated {
    if (!viewWillAppearCalled) {
        viewWillAppearCalled = YES;

        /* do stuff */
    }
}

Then you could safely call it manually for compatibility with iOS 4.x .

Same thing can be done for viewDidAppear, viewWillDisappear and viewDidDisappear.