Getting Initial View Controller from Storyboard inside the App Delegate

问题

I am trying to access the initial viewcontroller of my storyboard. It is a navigation controller which is wired up to a second viewcontroller via a seque. So after my application did finish launching I want to directly show the viewController that is connected through the segue. I tried it out with code like this but it doesn't work ...

UINavigationController *navController = (UINavigationController*)self.window.rootViewController;
[navController.topViewController performSegueWithIdentifier:@"showLoginScreen" sender:self];

What am I doing wrong?

4 years later:

If I look at my question again after 4 years, I honestly have no idea what my real problem was.

回答1:

Be sure you have tick marked the

is initial ViewController

option for UINavigationController in storyBoard

UIStoryboard* storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
UINavigationController * myStoryBoardInitialViewController = [storyboard instantiateInitialViewController];

回答2:

Sebastian, I'm not sure why you would want to start the initial view controller manually - all my projects (which all use storyboards) do this automatically if you ticked "Use Storyboards" on the second screen in the "New Project" wizard.

Maybe you need to mark the storyboard scene as inital? This can be done in the scene's attribute inspector by ticking the "Is Initial View Controller" - rather obviously named.

And then - if you really have a unusual setup which requires you to access the scenes manually, you can use the following:

UIStoryboard *sb = [UIStoryboard storyboardWithName: "StoryboardName"
                                             bundle: [NSBundle mainBundle]];
UIViewController *vc = [sb instantiateInitialViewController];

(Beware - no code completion here, so check spelling again.)

Or maybe I am getting your question completely wrong..? Happy hacking!

回答3:

In my app i have tabBar

UIStoryboard *storyBoard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];

TabBarController *tabBar = [storyBoard instantiateViewControllerWithIdentifier:@"TabBarController"];

_window.rootViewController = tabBar;

来源：https://stackoverflow.com/questions/13289158/getting-initial-view-controller-from-storyboard-inside-the-app-delegate