Warning: Attempt to present UINavigationController on SampleViewController: whose view is not in the window hierarchy - xcode4

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];
}
}