How to add a right bar button to a navigation bar in iphone

Question

I want to add a right bar button item to the navigation bar, so that on click, it performs certain a function.

I have created the following code to add the right bar button item, but after it is done, the bar button item is not getting displayed in navigation bar:

-(void)viewDidload{
    self.navigationItem.rightBarButtonItem = 
    [[[UIBarButtonItem alloc] 
           initWithBarButtonSystemItem:UIBarButtonSystemItemAdd                                                                                                     
                                target:self
                                action:@selector(Add:)] autorelease];    
}

-(IBAction)Add:(id)sender
{
    TAddNewJourney *j=[[TAddNewJourney alloc]init];
    [app.navigationController pushViewController:j animated:YES];
    [j release];
}

Answer 1

Let assume, you have a UIViewController, like this:

UIViewController *vc = [UIViewController new];

And you added it to navigation controller:

UINavigationController *nc = [[UINavigationController alloc] initWithRootViewController:vc];

In this way rightBarButtonItem will NOT getting displayed:

nc.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"xyz" style:UIBarButtonItemStyleDone target:self action:@selector(xyz)];

BUT this way IT WILL appear:

vc.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"xyz" style:UIBarButtonItemStyleDone target:self action:@selector(xyz)];

Use your own viewcontroller instead of the navigationcontroller to refer navigationItem.