以编程方式创建一个 navigationController (Swift)

Question

I've been trying to redo the work on my app programmatically. (Without the use of storyboards)

I'm almost done, except making the navigation controller manually.

I've been doing some research but I can't find any documentation of implementing this manually. (I started making the app as a Single View Application)

Currently, I only have 1 viewcontroller. And of course the appDelegate

The navigation Controller, will be used throughout all pages in the application.

If anyone could help me out, or send a link to some proper documentation for doing this programmatically it would be greatly appreciated.

EDIT:

I forgot to mention it's in Swift.

Answer 1

Swift 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()
}

Swift 4+: and Swift 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()
}

Answer 2

I would recommend starting your AppDelegate with this skeleton:

1) use let wherever you can!

2) UINavigationController has the rootViewController property.

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
}

Answer 3

Value of type 'AppDelegate' has no member 'window'

For those building newer projects with SceneDelegate.swift, you can use the 'var window: UIWindow?' in SceneDelegate instead of the removed 'var window' in AppDelegate

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
}

Answer 4

Try this one . It will guide you how to use navigation controller.

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

AppDelegate.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];
  }

Then when you want to push the other view controller , simple use following code to move to another view controller.

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

Answer 5

Here is another take in the SceneDelegate class:

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()
        }
}

Answer 6

It is probably overkill, but I find myself doing this often enough that I just extended UIViewController and created an embedInNavigationController method. So now I can just call viewController.embedInNavigationController.

extension UIViewController {

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

Answer 7

 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() 
}