Make a custom back button for UINavigationController

Question

I'm developping an app for iOS 4.2+. I subclassed my UINavigationController to insert two UIImageView and make the navigation bar look custom. Everything is working great but I have a little problem. I created custom UIBarButtonItem and inside my view controllers i put them with :

self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc]initWithCustomView:backButton];

It works too but the problem is that to make this work I need to call it from:

 - (void)viewDidAppear:(BOOL)animated ;

So it only appears after the animation and I can see the non customized button 1 second before the customized one replace it.

(I tried with viewWillAppear but then nothing append in navigationbar)

I would like to know if you have a solution that could correct this problem.

PS: I never use IB, everything is made programmatically.

Thanks from France !

EDIT 1: here is the code that didn't show anything for viewWillAppear:

- (void)viewWillAppear:(BOOL)animated  {
    [self setTitle:@"Jeu"];

    //Bouton testflight
    TIFButton *testFeedbackButton = [[TIFButton alloc]init];
    [testFeedbackButton setTitle: @"Envoyer un Feedback" forState:UIControlStateNormal];
    [testFeedbackButton addTarget:self action:@selector(launchFeedback) forControlEvents:UIControlEventTouchUpInside];

    UIBarButtonItem *testFeedback = [[UIBarButtonItem alloc] initWithCustomView:testFeedbackButton];

    self.navigationItem.rightBarButtonItem = testFeedback;  

    TIFBackButton *backButton = [[TIFBackButton alloc]init];
    [backButton setTitle: @"Retour" forState:UIControlStateNormal];
    [backButton addTarget:self action:@selector(popToPrecedentViewController) forControlEvents:UIControlEventTouchUpInside];

    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc]initWithCustomView:backButton];
}

Answer 1

Let's say you have two ViewControllers, A and B, you're pushing B onto the stack when A is topmost, and you want to customize the back button that shows up when B is on top.

Typically, the way to do this is to set ViewController A's navigationItem.backBarButtonItem.

Instead, what you're doing is to give ViewController B a custom button on the left side of the navbar by setting its navigationItem.leftBarButtonItem.

You've implemented that approach fine, except that even if you don't set ViewController A's navigationItem.backBarButtonItem, by default you still get a default back button as well. So that button is probably showing up on top of your custom back button.

If you set ViewController B's navigationItem.hidesBackButton = YES then you shouldn't have any problem.

And in the future, when you implement custom back buttons, you should do it by setting navigationItem.backBarButtonItem instead of navigationItem.leftBarButtonItem. The one adjustment you'll have to make is that with this approach, for example you would use ViewController A's navigationItem to change the back button that shows up when ViewController B is on top.