delegate to Storyboard created View Controller - swift

Question

i created two projects to learn how the delegate method is working..
one project created WITHOUT storyboard, just via code and my delegate is working just fine.
i built the other Project WITH storyboard, which means all ViewControllers are visible in the Interfacebuilder..
i am sure the issue lays in the definition of the ViewControllers in the code file:
let homeVC = HomeViewController()
Can someone please tell what is wrong here?
import UIKit
protocol HomeViewControllerDelegate: AnyObject {
func showMenu()
}
class HomeViewController: UIViewController {
var delegate: HomeViewControllerDelegate?
override func viewDidLoad() {
title = "App"
super.viewDidLoad()
configureNaviBar()
}
func configureNaviBar() {
// Left Bar Button Item
let burgerButton = UIImage(systemName: "line.horizontal.3")
self.navigationItem.leftBarButtonItem = UIBarButtonItem(image: burgerButton, style: .plain, target: self, action: #selector(showMenu))
}
#objc func showMenu(sender: AnyObject) {
print("show Menu (home)")
// homeDelegate is nil?
delegate!.showMenu() // throws an error!
}
}
import UIKit
class MainViewController: UIViewController {
let naviVC:UIViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "NaviVC") as! NaviVC
let menuVC:UIViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "SideMenuID") as! SideMenuViewController
let homeVC = HomeViewController()
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .green
setupContainerView()
}
func setupContainerView() {
// menu
addChild(menuVC)
self.view.addSubview(menuVC.view)
menuVC.view.frame = CGRect(x: 0, y: 0, width: 200, height: 896)
menuVC.didMove(toParent: self)
// Home
homeVC.delegate = self
addChild(naviVC)
self.view.addSubview(naviVC.view)
naviVC.view.frame = self.view.bounds
naviVC.didMove(toParent: self)
}
}
extension MainViewController: HomeViewControllerDelegate {
func showMenu() {
// does not get called
print("did tap menu")
}
}
Error:
Debug_project/HomeViewController.swift:49: Fatal error: Unexpectedly found nil while unwrapping an Optional value
i am already searching for days now, and just can't find the solution for this...
please help me out guys

Answer 1

I found the solution!
Tanks to Phillip Mills and all others for helping me find this..
the solution is:
change
let homeVC = HomeViewController()
to
override func viewDidLoad() {
super.viewDidLoad()
let homeVC = naviVC.viewControllers.first as! HomeViewController // working: this is it!
}
class MainViewController: UIViewController {
let naviVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "NaviVC") as! NaviVC
let menuVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "SideMenuID") as! SideMenuViewController
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .green
setupContainerView()
}
func setupContainerView() {
// menu
addChild(menuVC)
self.view.addSubview(menuVC.view)
menuVC.view.frame = CGRect(x: 0, y: 0, width: 200, height: 896)
menuVC.didMove(toParent: self)
// Home
let homeVC = naviVC.viewControllers.first as! HomeViewController // working: this is it!
homeVC.delegate = self
addChild(naviVC)
self.view.addSubview(naviVC.view)
naviVC.view.frame = self.view.bounds
naviVC.didMove(toParent: self)
}
}
extension MainViewController: HomeViewControllerDelegate {
func showMenu() {
// does not get called
print("did tap menu")
}
}