在NavigationBar中更改后退按钮的标题

Question

Following the examples of the many duplicates for this questions, I can't seem to get it right.

I have a UINavigationViewController that has a LoginViewController as the rootViewController. Here I got a button with a segue (push) to a LoginInfoViewController.

In LoginInfoViewController.m:

- (void)viewDidLoad
{
    [super viewDidLoad];

    //null
    NSLog(@"%@", self.navigationItem.backBarButtonItem);

    UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithTitle:@"Test"
                                                                   style:UIBarButtonItemStyleDone
                                                                  target:nil
                                                                  action:nil];
    self.navigationItem.backBarButtonItem = backButton;

    //not null, still the back button says: "Back"
    NSLog(@"%@", self.navigationItem.backBarButtonItem);
}

Answer 1

Set the title of the back button on the view BEFORE. So, if you segue from LoginViewController , you set the back button title on the item before you segue to LoginInfoViewController

Example:

In the viewDidLoad method on LoginViewController :

UIBarButtonItem *newBackButton = [[UIBarButtonItem alloc] initWithTitle: @"Go back" style: UIBarButtonItemStyleBordered target: nil action: nil];
[[self navigationItem] setBackBarButtonItem: newBackButton];

This means you're setting the button on the LoginViewController , not on the LoginInfoViewController .

Answer 2

You will need to set the backBarButtonItem of the controller you are going back to, not the controller you pushed. Move your code to the LoginViewController viewDidLoad method.

The navigation controller derives the back button for the navigation bar from the backBarButtonItem of the preceding controller in the stack. If the item is nil, it will use the value in the title property of same. If the title is too long to fit, the navigation bar may substitute the string "Back" in place of the title. If your controller has a custom left bar button item, the navigation bar will ignore the backButtonItem property and title presenting the custom button instead.