Btukfyl

I ignore storyboard and create UINavigationController in AppDelegate.swift

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

    // Override point for customization after application launch.



    window = UIWindow(frame: UIScreen.main.bounds)

    window?.makeKeyAndVisible()



    let layout = UICollectionViewFlowLayout()

    layout.scrollDirection = .horizontal

    window?.rootViewController = UINavigationController(rootViewController: HomeController(collectionViewLayout: layout))//make the ViewController class to be the root



    return true

}

I have leftBarButton which switches to another UINavigationController or UICollectionViewController(according to your advice)

override func viewDidLoad() {

    super.viewDidLoad()



    let parentMenuButton = UIButton(frame: CGRect(x: 0, y: 0, width: 34, height: 34))

    parentMenuButton.addTarget(self, action: #selector(self.menuButtonOnClicked), for: .touchUpInside)

    navigationItem.leftBarButtonItem = UIBarButtonItem(customView: parentMenuButton)

}



@objc func menuButtonOnClicked(){

    print("menuButtonOnClicked button is pressed")

}

How can I achieve this programmatically?(switch another navigation area by pressing menu button)

let storyboard = UIStoryboard(name: "Main", bundle: nil)

let secondViewController = storyboard.instantiateViewController(withIdentifier: "SecondViewController") as! SecondViewController

self.navigationController!.pushViewController(secondViewController, animated: true)

Error:

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

I create SecondViewController:

import UIKit



class SecondViewController: UIViewController {



    override func viewDidLoad() {

        super.viewDidLoad()



        // Do any additional setup after loading the view.

    }



}

Is there a way to do it without messing with storyboard?(only programatically)

You need to call push method in your menuButtonOnClicked()

 @objc func menuButtonOnClicked(){

    print("menuButtonOnClicked button is pressed")

    let storyboard = UIStoryboard(name: "Main", bundle: nil)

    let secondViewController = storyboard.instantiateViewControllerWithIdentifier("SecondViewController") as SecondViewController

    self.navigationController.pushViewController(secondViewController, animated: true)

    }