set initial viewcontroller in appdelegate - swift
I would like to set the initial viewcontroller from the appdelegate. I found a really good answer, however it's in Objective C and im having trouble achieving the same thing in swift.
Programmatically set the initial view controller using Storyboards
- (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;
}
Anyone able to help?
I want the initial Viewcontroller to be dependent on certain conditions being met using a conditional statement.
Solution 1:
Xcode11 and SceneDelegate note:
Starting from Xcode11, because of SceneDelegates, it's likely that you shouldn't do it inside AppDelegate
. Instead do it from SceneDelegate
. For more on that see this other answer
Old answer:
I used this thread to help me convert the objective C to swift, and its working perfectly.
Instantiate and Present a viewController in Swift
Swift 2 code:
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let initialViewController = storyboard.instantiateViewControllerWithIdentifier("LoginSignupVC")
self.window?.rootViewController = initialViewController
self.window?.makeKeyAndVisible()
return true
}
Swift 3 code:
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
self.window = UIWindow(frame: UIScreen.main.bounds)
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let initialViewController = storyboard.instantiateViewController(withIdentifier: "LoginSignupVC")
self.window?.rootViewController = initialViewController
self.window?.makeKeyAndVisible()
return true
}
Solution 2:
Try this. For example:
You should use UINavigationController
as the initial view controller. Then, you can set any view controller as root from the storyboard.
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
// Override point for customization after application launch.
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let navigationController = storyboard.instantiateInitialViewController() as UINavigationController
let rootViewController = storyboard.instantiateViewControllerWithIdentifier("VC") as UIViewController
navigationController.viewControllers = [rootViewController]
self.window?.rootViewController = navigationController
return true
}
See my storyboard screen.
Solution 3:
For new Xcode 11.xxx and Swift 5.xx, where the target it set to iOS 13+.
For the new project structure, AppDelegate does not have to do anything regarding rootViewController.
A new class is there to handle window(UIWindowScene) class -> 'SceneDelegate' file.
class SceneDelegate: UIResponder, UIWindowSceneDelegate {
var window: UIWindow?
func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
if let windowScene = scene as? UIWindowScene {
let window = UIWindow(windowScene: windowScene)
window.rootViewController = // Your RootViewController in here
self.window = window
window.makeKeyAndVisible()
}
}
Solution 4:
Swift 3, Swift 4:
Change first line to
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool
the rest is same.
Swift 5+:
Instantiate root view controller from storyboard:
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
// this line is important
self.window = UIWindow(frame: UIScreen.main.bounds)
// In project directory storyboard looks like Main.storyboard,
// you should use only part before ".storyboard" as its name,
// so in this example name is "Main".
let storyboard = UIStoryboard.init(name: "Main", bundle: nil)
// controller identifier sets up in storyboard utilities
// panel (on the right), it is called 'Storyboard ID'
let viewController = storyboard.instantiateViewController(withIdentifier: "YourViewControllerIdentifier") as! YourViewController
self.window?.rootViewController = viewController
self.window?.makeKeyAndVisible()
return true
}
If you want to use UINavigationController
as root:
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
// this line is important
self.window = UIWindow(frame: UIScreen.main.bounds)
let storyboard = UIStoryboard.init(name: "Main", bundle: nil)
let viewController = storyboard.instantiateViewController(withIdentifier: "YourViewControllerIdentifier") as! YourViewController
let navigationController = UINavigationController.init(rootViewController: viewController)
self.window?.rootViewController = navigationController
self.window?.makeKeyAndVisible()
return true
}
Instantiate root view controller from xib:
It is almost the same, but instead of lines
let storyboard = UIStoryboard.init(name: "Main", bundle: nil)
let viewController = storyboard.instantiateViewController(withIdentifier: "YourViewControllerIdentifier") as! YourViewController
you'll have to write
let viewController = YourViewController(nibName: "YourViewController", bundle: nil)