Ios 尝试更改根视图控制器时，应用程序委派因NSException而崩溃

尝试在第一次运行应用程序后更改根视图控制器，但它崩溃

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?


    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        if(UserDefaults.standard.bool(forKey: "notFirstInApp") == false){
            UserDefaults.standard.set(true, forKey: "notFirstInApp")
            let state = StateTableViewController()
            window?.rootViewController = state
        }else{
            let home = HomeViewController()
            window?.rootViewController = home
        }

        return true
    }

撞车

libc++abi.dylib:以NSException（lldb）类型的未捕获异常终止

---

提前感谢。

您不能通过viewController名称直接设置rootViewController。请检查下面的代码

let storyboard = UIStoryboard(name: "Main", bundle: nil)
let initialViewController = storyboard.instantiateViewController(withIdentifier: "LoginSignupVC")
self.window?.rootViewController = initialViewController
self.window?.makeKeyAndVisible()

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这不是初始化ViewController的正确方法。详情请参阅此答案