Modify the More button on the Navigation bar of a tab displayed from a UITabBarController's More tab

Question

I have an app with a UITabBarController that has more than five tabs.

When I press the More tab, I go to the moreNavigationController which is a UINavigationController .

As you can see, I have figured out how to style the Title , Tint , Table color , and the Edit button on the More screen, as well as the Configure screen from pressing the Edit button.

What I have not been able to figure out is how to style the back button, titled More , when I select an item in the table.

Each tab has it's own class, GRWTabSettingsViewController for example, which inherits from GRWViewController , which provides common functionality for all tabs, which then inherits from UIViewController .

When on the Settings screen (or any other tab), I am trying to edit the More back button.

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

    [(UIBarButtonItem *)[(UINavigationItem *)[(UINavigationBar *)[(UINavigationController *)[self navigationController] navigationBar] topItem] leftBarButtonItem] setTintColor:[UIColor darkGrayColor]]; 
    [self.navigationController.navigationBar.topItem.leftBarButtonItem setTintColor:[UIColor darkGrayColor]];
}

However, this navigationController is clearly the parent since these changes get applied to the More screen and not the Settings screen.

What am I misunderstanding and how would I modify the buttons displayed on the navigation bar of the screen I am viewing?

=== SOLUTION ===

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

    // use backBarButtonItem not leftBarButtonItem
    //[(UIBarButtonItem *)[(UINavigationItem *)[(UINavigationBar *)[(UINavigationController *)[self navigationController] navigationBar] topItem] leftBarButtonItem] setTintColor:[UIColor darkGrayColor]];
    //[self.navigationController.navigationBar.topItem.leftBarButtonItem setTintColor:[UIColor darkGrayColor]];

    UIBarButtonItem *backButton = [[UIBarButtonItem alloc]
                                   initWithTitle:self.navigationController.navigationBar.topItem.title
                                   style:UIBarButtonItemStylePlain
                                   target:nil
                                   action:nil];
    [backButton setTintColor:[UIColor darkGrayColor]];

    self.navigationController.navigationBar.topItem.backBarButtonItem = backButton;
    // these do not work
    //[self.navigationController.navigationBar.topItem.backBarButtonItem setTintColor:[UIColor darkGrayColor]];
    //[backButton setTintColor:[UIColor darkGrayColor]];
}

Did take me a while to figure out that I can not format the button through self , or format the button after the assignment to self .

Answer 1

你应该定制backBarButtonItem以前的导航项目的，不是的topItem 。