How to add a right button to a UINavigationController?

Question

I am trying to add a refresh button to the top bar of a navigation controller with no success.

Here is the header:

@interface PropertyViewController : UINavigationController {

}

Here is how I am trying to add it:

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
        UIBarButtonItem *anotherButton = [[UIBarButtonItem alloc] initWithTitle:@"Show" style:UIBarButtonItemStylePlain
                                          target:self action:@selector(refreshPropertyList:)];      
        self.navigationItem.rightBarButtonItem = anotherButton;
    }
    return self;
}

Answer 1

Try doing it in viewDidLoad. Generally you should defer anything you can until that point anyway, when a UIViewController is inited it still might be quite a while before it displays, no point in doing work early and tying up memory.

- (void)viewDidLoad {
  [super viewDidLoad];

  UIBarButtonItem *anotherButton = [[UIBarButtonItem alloc] initWithTitle:@"Show" style:UIBarButtonItemStylePlain target:self action:@selector(refreshPropertyList:)];          
  self.navigationItem.rightBarButtonItem = anotherButton;
  [anotherButton release];
}

As to why it isn't working currently, I can't sat with 100% certainty without seeing more code, but a lot of stuff happens between init and the view loading, and you may be doing something that causes the navigationItem to reset in between.

Answer 2

Why are you subclasses UINavigationController? There is no need to subclass it if all you need to do is add a button to it.

Set up a hierarchy with a UINavigationController at the top, and then in your root view controller's viewDidLoad: method: set up the button and attach it to the navigation item by calling

[[self navigationItem] setRightBarButtonItem:myBarButtonItem];

Answer 3

Try adding the button to the navigationItem of the view controller that is going to be pushed onto this PropertyViewController class you have created.

That is:

MainViewController *vc = [[MainViewController alloc] initWithNibName:@"MainViewController" bundle:nil];
UIButton *infoButton = [UIButton buttonWithType:UIButtonTypeInfoLight];
[infoButton addTarget:self action:@selector(showInfo) forControlEvents:UIControlEventTouchUpInside];
vc.navigationItem.rightBarButtonItem = [[[UIBarButtonItem alloc] initWithCustomView:infoButton] autorelease];

PropertyViewController *navController = [[PropertyViewController alloc] initWithRootViewController:vc];

Now, this infoButton that has been created programatically will show up in the navigation bar. The idea is that the navigation controller picks up its display information (title, buttons, etc) from the UIViewController that it is about to display. You don't actually add buttons and such directly to the UINavigationController.

Answer 4

@Artilheiro : If its a navigationbased project, u can create BaseViewController. All other view will inherit this BaseView. In BaseView u can define generic methods to add right button or to change left button text.

ex:

@interface BaseController : UIViewController {

} - (void) setBackButtonCaption:(NSString *)caption;

(void) setRightButtonCaption:(NSString *)caption selectot:(SEL )selector;

@end // In BaseView.M

(void) setBackButtonCaption:(NSString *)caption {

UIBarButtonItem *backButton =[[UIBarButtonItem alloc] init];

backButton.title= caption;
self.navigationItem.backBarButtonItem = backButton;
[backButton release];

} - (void) setRightButtonCaption:(NSString *)caption selectot:(SEL )selector {

  UIBarButtonItem *rightButton = [[UIBarButtonItem alloc] init];

rightButton.title = caption;

rightButton.target= self;

[rightButton setAction:selector];

self.navigationItem.rightBarButtonItem= rightButton;

[rightButton release];

}

And now in any custom view, implement this base view call the methods:

@interface LoginView : BaseController {

In some method call base method as:

SEL sel= @selector(switchToForgotPIN);

[super setRightButtonCaption:@"Forgot PIN" selectot:sel];