Question

- (void)viewDidLoad
{
    [super viewDidLoad];

    ac = [[AddContacts alloc]init];
    self.navigationController = [[UINavigationController alloc] initWithRootViewController:ac];
    [self.view addSubview:navigationController.view];

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

Why is my button not being added on the navigation controller?

Answer 1

The UIBarButtonItems are not controlled by the navigation controller, but by each of the view controllers it contains – each UIViewController can have different buttons. Try:

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

Then initialize the UINavigationController as you have been doing.