Warning: Attempt to present UINavigationController on SampleViewController: whose view is not in the window hierarchy

Question

i have try all the solution in this forum but still cannot solve. Can anybody help me out with these problem? i want the app to open the inboxData class that contain a tableView when the NSUserDefault read the key @"url" from Urban Airship..

this is from SampleViewController class;

-(void)viewDidAppear:(BOOL)animated{

    [super viewDidAppear:animated];

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    NSString *action_9 = [defaults objectForKey:@"url"];

    if ([[[NSUserDefaults standardUserDefaults]objectForKey:@"url"] isEqualToString:@"aa9"])

{

        inboxData *screen=[[inboxData alloc]initWithNibName:@"inboxData" bundle:nil];
        screen.strGetTableSelect=@"1";
        UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:screen];
        [self presentModalViewController:navigationController animated:YES];

    }
}

it return with these error..

Warning: Attempt to present UINavigationController on SampleViewController whose view is not in the window hierarchy

Answer 1

Your SampleViewController not in the Window hierarchy, You need to set in window.

In your appDelegate, do like this,

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    self.viewController = [[SampleViewController alloc] initWithNibName:@"SampleViewController" bundle:nil];
    self.navigationController = [[UINavigationController alloc] initWithRootViewController:self.viewController];
    self.window.rootViewController = self.navigationController;
    [self.window makeKeyAndVisible];
    return YES;
}

If you are using storyboad, Use like this in didFinishLaunchingWithOptions method,

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"MainStoryboard_iPhone"
                                                             bundle: nil];
 
    SampleViewController *mainViewController = (SampleViewController*)[mainStoryboard
                                                       instantiateViewControllerWithIdentifier: @"SampleViewController"];
 
    UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:mainViewController];
 
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    [self.window setRootViewController:navigationController];
    [self.window setBackgroundColor:[UIColor whiteColor]];
    [self.window makeKeyAndVisible];
 
    return YES;
}

In your view controller,

-(void)viewDidAppear:(BOOL)animated{

    [super viewDidAppear:animated];

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    NSString *action_9 = [defaults objectForKey:@"url"];

    if ([[[NSUserDefaults standardUserDefaults]objectForKey:@"url"] isEqualToString:@"aa9"])

{
        inboxData *screen=[[inboxData alloc]initWithNibName:@"inboxData" bundle:nil];
        screen.strGetTableSelect=@"1";
        [self presentModalViewController:screen animated:YES];

    }
}