IOS: start a tabbarcontroller in a secondviewcontroller - ios

Question

I want set a tabbar in my app and in my appDelegate I do this:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
// Override point for customization after application launch.
UIViewController *viewController1 = [[[FirstViewController alloc] initWithNibName:#"FirstViewController" bundle:nil] autorelease];
UIViewController *viewController2 = [[[SecondViewController alloc] initWithNibName:#"SecondViewController" bundle:nil] autorelease];
[viewController2 viewDidLoad];
UIViewController *viewController3 = [[[ThirdViewController alloc] initWithNibName:#"ThirdViewController" bundle:nil] autorelease];
[viewController3 viewDidLoad];
UIViewController *viewController4 = [[[FourthViewController alloc] initWithNibName:#"FourthViewController" bundle:nil] autorelease];
[viewController4 viewDidLoad];
self.tabBarController = [[[UITabBarController alloc] init] autorelease];
self.tabBarController.viewControllers = #[viewController1, viewController2, viewController3, viewController4];
self.viewController = [[[HomeViewController alloc] initWithNibName:#"HomeViewController" bundle:nil] autorelease];
self.window.rootViewController = self.viewController;
[self.window makeKeyAndVisible];
return YES;
}
you can see that I want to start my app not immediately with tab bar, in fact I start my app with an HomeViewController
inside my HomeViewController i open viewController1 with:
FirstViewController *first = [[FirstViewController alloc]initWithNibName:#"FirstViewController" bundle:nil];
[self presentViewController:first animated:YES completion:nil];
[first release];
but in my firstviewcontroller I don't see my tabbar, why? (I state that the app work fine with tabbar if I start without homeviewcontroller)

Answer 1

You don't see tabbar because in HomeViewController you create new instance of FirstViewController and present it modally. You should create and present the whole UITabBarController inside HomeViewController:
AppDelegate:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
self.viewController = [[[HomeViewController alloc] initWithNibName:#"HomeViewController" bundle:nil] autorelease];
self.window.rootViewController = self.viewController;
[self.window makeKeyAndVisible];
return YES;
}
inside HomeViewController:
FirstViewController *viewController1 = [[[FirstViewController alloc] initWithNibName:#"FirstViewController" bundle:nil] autorelease];
SecondViewController *viewController2 = [[[SecondViewController alloc] initWithNibName:#"SecondViewController" bundle:nil] autorelease];
ThirdViewController *viewController3 = [[[ThirdViewController alloc] initWithNibName:#"ThirdViewController" bundle:nil] autorelease];
FourthViewController *viewController4 = [[[FourthViewController alloc] initWithNibName:#"FourthViewController" bundle:nil] autorelease];
self.tabBarController = [[[UITabBarController alloc] init] autorelease];
self.tabBarController.viewControllers = #[viewController1, viewController2, viewController3, viewController4];
[self presentViewController:self.tabBarController animated:YES completion:nil];