Adding Label on Application Window from app delegate - objective-c

Question

I am using Xcode 4.5 and iOS 6.0, I have selected the default single view template from the xcode, I just want to add the label on the application window but I am unable to do so. Please correct me.
- (BOOL)application:(UIApplication *)application
didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
self.viewController = [[ViewController alloc] initWithNibName:#"ViewController" bundle:nil];
self.window.rootViewController = self.viewController;
label =[[UILabel alloc] initWithFrame:CGRectMake(100, 100, 200, 20)];
label.text = #"Test";
[label setBackgroundColor:[UIColor whiteColor]];
[self.window addSubview:label];
[self.window bringSubviewToFront:label];
[self.window makeKeyAndVisible];
return YES;
}
PS - I want my label on top of my ViewController view i.e. on the window so it will be always there despite changes in the views presented by window. I dont want to only show the label here.
I got the answer
[self.window.rootViewController.view addSubview:label];
Thanks all for giving the pointers.

Answer 1

Just Remove the RootviewController.
- (BOOL)application:(UIApplication *)application
didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
label =[[UILabel alloc] initWithFrame:CGRectMake(100, 100, 200, 20)];
label.text = #"Test";
[label setBackgroundColor:[UIColor whiteColor]];
[self.window addSubview:label];
[self.window bringSubviewToFront:label];
[self.window makeKeyAndVisible];
return YES;
}
if you dont want to only show the label here then use like below.
self.viewController = [[ViewController alloc] initWithNibName:#"ViewController" bundle:nil];
self.window.rootViewController = self.viewController;
[self.Viewcontroller.view addSubview:label];

Answer 2

Add the label to self.window.rootViewController.view instead of self.window
UILabel *label =[[UILabel alloc] initWithFrame:CGRectMake(100, 100, 200, 20)];
label.text = #"Test"; [label setBackgroundColor:[UIColor whiteColor]];
[self.window.rootViewController.view addSubview:label];