Programmatically set the initial view controller using Storyboards

How do I programmatically set the InitialViewController for a Storyboard? I want to open my storyboard to a different view depending on some condition which may vary from launch to launch.

Solution 1:

How to without a dummy initial view controller

Ensure all initial view controllers have a Storyboard ID.

In the storyboard, uncheck the "Is initial View Controller" attribute from the first view controller.

If you run your app at this point you'll read:

Failed to instantiate the default view controller for UIMainStoryboardFile 'MainStoryboard' - perhaps the designated entry point is not set?

And you'll notice that your window property in the app delegate is now nil.

In the app's setting, go to your target and the Info tab. There clear the value of Main storyboard file base name. On the General tab, clear the value for Main Interface. This will remove the warning.

Create the window and desired initial view controller in the app delegate's application:didFinishLaunchingWithOptions: method:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:UIScreen.mainScreen.bounds];

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

    UIViewController *viewController = // determine the initial view controller here and instantiate it with [storyboard instantiateViewControllerWithIdentifier:<storyboard id>];

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

    return YES;
}

Solution 2:

For all the Swift lovers out there, here is the answer by @Travis translated into SWIFT:

Do what @Travis explained before the Objective C code. Then,

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

    self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
    let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
    var exampleViewController: ExampleViewController = mainStoryboard.instantiateViewControllerWithIdentifier("ExampleController") as! ExampleViewController

    self.window?.rootViewController = exampleViewController

    self.window?.makeKeyAndVisible()

    return true
}

The ExampleViewController would be the new initial view controller you would like to show.

The steps explained:

1. Create a new window with the size of the current window and set it as our main window
2. Instantiate a storyboard that we can use to create our new initial view controller
3. Instantiate our new initial view controller based on it's Storyboard ID
4. Set our new window's root view controller as our the new controller we just initiated
5. Make our new window visible

Enjoy and happy programming!

Solution 3:

You can programmatically set the key window's rootViewController in (BOOL)application:(UIApplication *)application willFinishLaunchingWithOptions:(NSDictionary *)launchOptions

for example:

- (BOOL)application:(UIApplication *)application willFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    if (shouldShowAnotherViewControllerAsRoot) {
        UIStoryboard *storyboard = self.window.rootViewController.storyboard;
        UIViewController *rootViewController = [storyboard instantiateViewControllerWithIdentifier:@"rootNavigationController"];
        self.window.rootViewController = rootViewController;
        [self.window makeKeyAndVisible];
    }

    return YES;
}