Set title and add button to navigation controller - objective-c

Question

I created a navigation controller but i can not set title or add button to the navigation bar.How to do that?
This is the code of application DidFinishLauchingOption in file AppDelegate.m :
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:view];
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
self.window.backgroundColor = [UIColor whiteColor];
self.view = [[ViewController alloc] init];
self.window.rootViewController = self.view;
[self.window addSubview:navController.view];
[self.window makeKeyAndVisible];
return YES;
}
Thanks in advance.

Answer 1

You need to set the rootViewController property of your window object to the navigation controller, rather than your instance of `ViewController. This should point you in the right direction:
#implementation AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
// Create and configure a window
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.window.backgroundColor = [UIColor whiteColor];
// Create a view controller
UIViewController *viewController = [[ViewController alloc] init];
// Create a navigation controller and set its root view controller to the instance of `ViewController`
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:viewController];
// Add the navigation controller to the window
self.window.rootViewController = navController;
[self.window makeKeyAndVisible];
return YES;
}
// ...
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
// Set the view controller's title
self.title = NSLocalizedString(#"View Controller", #"");
// Add a navigation bar button
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemRefresh target:self action:#selector(refreshButtonPressed:)];
}
- (void)refreshButtonPressed:(id)sender
{
// Do something when the refresh button is pressed.
}
// ...
#end

Answer 2

To create your initial setup, you create a navigation controller with your view controller and set it as the root view controller of your app delegate window:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
//create window
[self setWindow:[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]];
//create and set root view controller
[[self window] setRootViewController:[[UINavigationController alloc] initWithRootViewController:[[RootViewController alloc] init]]];
//make window key and visible
[self.window makeKeyAndVisible];
//bail
return YES;
}
Then in your view controller, set the title and add your navigation item:
- (void)viewWillAppear:(BOOL)animated
{
//call parent implementation
[super viewWillAppear:animated];
//set view controller title
[self setTitle:#"Root View Controller"];
//add navigation bar button
[[self navigationItem] setRightBarButtonItem:[[UIBarButtonItem alloc] initWithTitle:#"Button Title" style:UIBarButtonItemStyleBordered target:self action:#selector(handleBarButtonItemEvents:)]];
}
And listen for button events via:
- (void)handleBarButtonItemEvents:(id)sender
{
//
}