AppDelegate didFinishLaunchingWithOptions launchOptions - terminating with uncaught exception of type NSException Swift 3.0

Question

I'm trying to create login/protected page session page using Swift 3.0

Therefore, I created didFinishLaunchingWithOptions launchOptions function in AppDelegate.swift as below

AppDelegate.swift

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        // Override point for customization after application launch.


        let rootViewController = self.window!.rootViewController
        let mainStoryBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)

        let isUserLoggedIn:Bool = UserDefaults.standard.bool(forKey: "isUserLoggedIn")
        if(!isUserLoggedIn){

            let loginViewController = mainStoryBoard.instantiateViewController(withIdentifier: "loginview") as! LoginVC

            window!.rootViewController = loginViewController
            window!.makeKeyAndVisible()

        }
        else{
            let protectedPage = mainStoryBoard.instantiateViewController(withIdentifier: "ViewController") as! ViewController

            window!.rootViewController = protectedPage
            window!.makeKeyAndVisible()
        }

        return true
    }
}

It build successfully, But i got an error when apps run. The error as below

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Storyboard () doesn't contain a view controller with identifier 'loginview''

libc++abi.dylib: terminating with uncaught exception of type NSException (lldb)

Answer 1

在情节提要中选择LoginVC，然后在检查器窗口中的情节提要ID中提供loginview标识符

Answer 2

Most probably, you did not set the Storyboard ID of your LoginVC. Select the LoginVC in storyboard and set the storyboard ID as "loginview". See the image for reference