how show navigation bar in swift code example

Example 1: swift add navigation bar

override func viewDidLoad() {
    super.viewDidLoad()
    self.setNavigationBar()
}

func setNavigationBar() {
        let screenSize: CGRect = UIScreen.main.bounds
        let navBar = UINavigationBar(frame: CGRect(x: 0, y: 0, width: screenSize.width, height: 44))
        let navItem = UINavigationItem(title: "")
        let doneItem = UIBarButtonItem(barButtonSystemItem: UIBarButtonItem.SystemItem.done, target: nil, action: #selector(dissmissView))
        navItem.rightBarButtonItem = doneItem
        navBar.setItems([navItem], animated: false)
        self.view.addSubview(navBar)
    }

@objc
    func dissmissView(){
        self.dismiss(animated: true, completion: nil)
    }

Example 2: swift add navigation bar

let navBar = UINavigationBar(frame: CGRect(x: 0, y: 0, width: view.frame.size.width, height: 44))
view.addSubview(navBar)

let navItem = UINavigationItem(title: "SomeTitle")
let doneItem = UIBarButtonItem(barButtonSystemItem: .done, target: nil, action: #selector(selectorName:))
navItem.rightBarButtonItem = doneItem

navBar.setItems([navItem], animated: false)