iphone - Tabbar application with NavigationController, without MainWindow.xib - iphone

Question

Hihi all,
I am pretty new in iPhone dev. I have follow some tutorial and created a tabbar application. Below is the code in the appdelegate implementation:
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
UIViewController *viewController1 = [[ViewController1 alloc] initWithNibName:#"ViewController1" bundle:nil];
UIViewController *viewController2 = [[ViewController2 alloc] initWithNibName:#"ViewController2" bundle:nil];
self.tabBarController = [[UITabBarController alloc] init];
self.tabBarController.viewControllers = [NSArray arrayWithObjects:viewController1, viewController2, nil];
self.window.rootViewController = self.tabBarController;
[self.window makeKeyAndVisible];
Then set the title and the image for the tab in each of the controller implementation.
My problem is that, example, in my viewController1, I need to navigate to viewController3, when I use presentModalViewController method to push the viewController3 in, the tabbar at the bottom will be disappeared.
While I tried to use the app delegate to refer to my tabBarController, and use tabBarController.navigationController pushViewController method, my viewController3 is not being pushed, and seems nothing happens.
I have tried to follow a few tutorial, but it's all required to drag in the navigationcontroller into the MainWindow.xib, which, in the xcode 4, MainWindow.xib doesn't exist anymore. How can i create the navigationcontroller from code so that the app can navigate between different view without hiding the tabbar?
Any comment is very much appreciated! Thanks in advance!
:)

Answer 1

If you want to use a navigation controller, you need to create a navigation controller. Since you're not using a XIB, you'll have to create it manually.
Since you want the tab bar to remain visible when you present viewController3, you need to make the navigation controller a child of the tab bar controller.
UIViewController *viewController1 = [[ViewController1 alloc] initWithNibName:#"ViewController1" bundle:nil];
UINavigationController *navController1 = [[UINavigationController alloc] initWithRootViewController:viewController1];
UIViewController *viewController2 = [[ViewController2 alloc] initWithNibName:#"ViewController2" bundle:nil];
self.tabBarController = [[UITabBarController alloc] init];
self.tabBarController.viewControllers = [NSArray arrayWithObjects:
navController1,
viewController2,
nil];
Then when you want to present viewController3, do this:
// in some method of viewController1
[self.navigationController pushViewController:viewController3 animated:YES];

Answer 2

I am not very Sure but have you tried this??? Actually i am going to use XCode 4 soon, i am still using 3.2.8 version:-
WebViewController *viewController = [[WebViewController alloc]initWithNibName:#"WebViewController" bundle:nil];
viewController.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:viewController animated:YES];
[viewController release];
See in this also the Tab bar will be removed when you navigate to your 3rd screen, you have to provide the navigation bar to come back.
Hope it helps.. :)