issue in hiding navigation bar

Question

i add navigation bar in rootController like below in appdelegate

@property (strong, nonatomic) UINavigationController *navController;
@synthesize navController;


birthDateTableViewController =[[BirthDateTableViewController alloc]initWithNibName:@"BirthDateTableViewController" bundle:nil];



navController = [[[UINavigationController alloc]initWithRootViewController:birthDateTableViewController]autorelease];


[window addSubview:navController.view];
[window makeKeyAndVisible];
 return YES;

now as i want to hide it in other view because they have their own navigation bars so i use following code for hiding rootViewControllers navigation bar but its not hiding please tell me what i am doing wrong i do this for hiding in viewDidLoad

AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
[appDelegate.navController setNavigationBarHidden: YES animated:NO];

application get crash when it reach above line i have tried this which is not working [self.navigationController setNavigationBarHidden: YES animated:NO];

Answer 1

Your appDelegate doesn't have a link to the navController but your viewController has one! So change your code for:

[self.navigationController setNavigationBarHidden: YES animated:NO];

Answer 2

我认为这样会很好。

[self.navigationController setNavigationBarHidden: YES animated:YES];

Answer 3

Try this in your view controller's -(void)viewWillAppear method in which you don't want to show navigation bar.

- (void)viewWillAppear:(BOOL)animated
{
     self.navigationController.navigationBarHidden = YES;

    [super viewWillAppear:animated];
}

Answer 4

Rather using...

  [window addSubview:navController.view];

Use this...

  [window addSubview:self.navController];

And in your viewControllers, use this...

  self.navigationController.navigationBarHidden = YES;

Answer 5

For iOS < 6.0 use

[self.window addSubview:navigationController.view];

For iOS >= 6.0 use

[self.window setRootViewController:navigationController];