雨燕1、2：

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
   self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
   var nav1 = UINavigationController()
   var mainView = ViewController(nibName: nil, bundle: nil) //ViewController = Name of your controller
   nav1.viewControllers = [mainView]
   self.window!.rootViewController = nav1
   self.window?.makeKeyAndVisible()
}

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雨燕4+：雨燕5+

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
   self.window = UIWindow(frame: UIScreen.main.bounds)
   let nav1 = UINavigationController()
   let mainView = ViewController(nibName: nil, bundle: nil) //ViewController = Name of your controller
   nav1.viewControllers = [mainView]
   self.window!.rootViewController = nav1
   self.window?.makeKeyAndVisible()
}

类型“AppDelegate”的值没有成员“window”

对于那些使用SceneDelegate.swift构建较新项目的用户，您可以使用'var窗口：UIWindow？“，而不是AppDelegate中已删除的”var窗口

func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
    guard let windowScene = (scene as? UIWindowScene) else { return }

    window?.windowScene = windowScene
    window?.makeKeyAndVisible()

    let viewController = ViewController()
    let navViewController = UINavigationController(rootViewController: viewController)
    window?.rootViewController = navViewController
}

我建议使用以下框架启动AppDelegate：
1)尽可能使用let！
2)UINavigationController具有rootViewController属性。

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    let viewController = ViewController(nibName: nil, bundle: nil) //ViewController = Name of your controller
    let navigationController = UINavigationController(rootViewController: viewController)

    self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
    self.window?.rootViewController = navigationController
    self.window?.makeKeyAndVisible()

    return true
}

下面是SceneDelegate类中的另一个镜头：

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)    
        let navController = UINavigationController()
        let viewController = ViewController()

        navController.viewControllers = [viewController]            
        window.rootViewController = navController
        self.window = window
        window.makeKeyAndVisible()
    }
}

试试这个，它会指导你如何使用导航控制器。
Programatically creating UINavigationController in iOS
AppDelegate.h

#import <UIKit/UIKit.h>
    #import "LoginViewController.h"

    @interface AppDelegate : UIResponder <UIApplicationDelegate>

    @property (strong, nonatomic) UIWindow *window;
    @property (strong,nonatomic) UINavigationController *navigationController;
    @property (strong,nonatomic) LoginViewController *loginVC;

    @end

应用委托.m

#import "AppDelegate.h"
    #import "LoginViewController.h"

    @implementation AppDelegate

  - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
  {
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.

   self.loginVC = [[LoginViewController alloc]initWithNibName:nil bundle:nil];
   self.loginVC.title = @"Login Page";

   self.navigationController = [[UINavigationController alloc]initWithRootViewController:self.loginVC];

   self.window.rootViewController = self.navigationController;
   [self.window makeKeyAndVisible];
  }

然后，当你想推送另一个视图控制器时，简单地使用下面的代码移动到另一个视图控制器。

- (IBAction)pushMyProfileView:(id)sender
{
    self.myProfileVC = [[MyProfileViewController alloc]initWithNibName:nil bundle:nil];
    [appDelegate.navigationController pushViewController:self.myProfileVC animated:YES];
}

这可能有点过头了，但我发现我经常这样做，所以我只是扩展了UIViewController并创建了一个embedInNavigationController方法，所以现在我可以调用viewController.embedInNavigationController。

extension UIViewController {

func embedInNavigationController() -> UINavigationController {
    return UINavigationController(rootViewController: self)
   }
}

self.window = UIWindow(frame: UIScreen.main.bounds) 
 let storyboard = UIStoryboard(name: "Main", bundle: nil) 
 let storyboard_Secondary = UIStoryboard(name: "Secondary", bundle: nil) 
 var initialViewController = UIViewController() 

 let aUser = CommonMethods.loadCustomObject("\(Constants.kUserProfile)") as? User  
 if aUser?.respCode == 1 { 
    initialViewController = storyboard_Secondary.instantiateViewController(withIdentifier: "MainTabVC")
    UIApplication.shared.statusBarStyle = .lightContent
    let navigationController = UINavigationController(rootViewController: initialViewController)
    navigationController.isNavigationBarHidden = true
    self.window!.rootViewController = navigationController
    self.window!.makeKeyAndVisible() 
}