iphone combined tab bar and navigationController

Im implementing a combined tab bar and navigation programatically, using the apple documentation,

it is not working when calling the initWithFrame,[goes black screen]; but if left as below code it works for showing main screen, with out the tab bar, and when using the tab bar goes black screen

here the code

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(  NSDictionary *)launchOptions {                  
self.tabBarController = [[[UITabBarController alloc] init] autorelease];
StartViewController *startViewControllerView = [[[StartViewController alloc] init] autorelease]; //ojo recomendado por apple!!!
VideosViewController* VideosViewController_ = [[[VideosViewController alloc] init] autorelease];
PhotosViewController* PhotosViewController_ = [[[PhotosViewController alloc] init] autorelease];
SocialViewController* SocialViewController_ = [[[SocialViewController alloc] init] autorelease];
self.pagesNavigation = [[[UINavigationController alloc] initWithRootViewController:startViewControllerView] autorelease];
self.pagesNavigation.navigationBarHidden = NO;
NSArray* controllers = [NSArray arrayWithObjects:VideosViewController_, PhotosViewController_, SocialViewController_, startViewControllerView, nil];
self.tabBarController.viewControllers = controllers;

[self.window addSubview:startViewControllerView.view];
//self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
[self.window makeKeyAndVisible];
  return YES;
}

so if left as shown above, it works but if I comment the addSubview and uncomment the initWithFrame, it doesnt wor开发者_JAVA百科k,,

  //[self.window addSubview:startViewControllerView.view];
self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];

So, what Im i missing?, what would be the right way to call the initWithFrame?

thanks a lot!

Why are all your viewcontrollers auto released? You should probably be retaining them and releasing them only when you're done with them.

As for your structure, I've found that building a single navigation controller for each tab in the tabbarcontroller, adding those to the controller, then adding the tabbarcontroller to the window works like this...

AppDelegate.h

property (nonatomic, retain) UITabBarController *tabBarController;
property (nonatomic, retain) UINavigationController *firstNavController;
property (nonatomic, retain) UINavigationController *secondNavController;
property (nonatomic, retain) FirstViewController *firstViewController;
property (nonatomic, retain) SecondViewController *secondViewController;

AppDelegate.m

firstViewController = [[FirstViewController alloc] someInitMethod:someArg];
firstNavController = [[UINavigationController alloc] initWithRootViewController:firstViewController]; 

secondViewController = [[SecondViewController alloc] someInitMethod:someArg];
secondNavController = [[UINavigationController alloc] initWithRootViewController:secondViewController]; 

tabBarController = [[UITabbarController alloc] init];

NSArray *tabs = [NSArray arrayWithObjects:firstNavController, secondNavController, nil];

[tabBarController setViewControllers:tabs animated:NO];

self.window.rootViewController = tabBarController;
[self.window makeKeyAndVisible];