How to Load View Controllers At the Beginning of the App? - xcode

Question

I have a Tab View Controller as my root controller in an App which consists of 3 tabs let's call them View A, View B, View C.
I want to load these tabs as soon as my app starts, I think it can be done within didFinishLaunchingWithOptions function but I'm not exactly sure, does anyone know how to do it?
Thanks

Answer 1

For these kinds of purposes I used this approach:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
UIWindow *window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.window = window;
UITabBarController *tabBarController = [[UITabBarController alloc] init];
rootView = [[SGMenuViewController alloc] init];
UIViewController *tab1VC = [[UIViewController alloc] init];
UIViewController *tab2VC = [[UIViewController alloc] init];
UIViewController *tab3VC = [[UIViewController alloc] init];
UIViewController *tab4VC = [[UIViewController alloc] init];
navController = [[UINavigationController alloc] initWithRootViewController:rootView];
UINavigationController *secondNavController = [[UINavigationController alloc] initWithRootViewController:tab3VC];
NSArray* controllers = [NSArray arrayWithObjects:navController, tab2VC, secondNavController, tab4VC, nil];
tabBarController.viewControllers = controllers;
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.window.rootViewController = tabBarController;
[self.window makeKeyAndVisible];
return YES;
}
You basically create a UITabBarController and you put all your view there. You create a UINavigationController if you need to push/pop views in the selected tab. In the example above only the 1st and the 3rd tab have UINavigationController and so I can use self.navigationController pushViewController: on them.