How to add custom view on right of navigation bar Swift?

Question

I am trying to add a custom view on right of UINavigationBar. What I tried is the following, but the view is not showing up! Pleas

Answer 1

Swift 3/4/5 Version of the Accepted Answer

let viewFN = UIView(frame: CGRect.init(x: 0, y: 0, width: 180, height: 40))
viewFN.backgroundColor = .yellow
let button1 = UIButton(frame: CGRect.init(x: 0, y: 0, width: 40, height: 20))
button1.setImage(UIImage(named: "notification"), for: .normal)
button1.setTitle("one", for: .normal)

button1.addTarget(self, action: #selector(self.didTapOnRightButton), for: .touchUpInside)
let button2 = UIButton(frame: CGRect.init(x: 40, y: 8, width: 60, height: 20))
button2.setImage(UIImage(named: "notification"), for: .normal)
button2.setTitle("tow", for: .normal)
let button3 = UIButton(frame: CGRect.init(x: 80, y: 8, width: 60, height: 20))
button3.setImage(UIImage(named: "notification"), for: .normal)
button3.setTitle("three", for: .normal)

button3.addTarget(self, action: #selector(self.didTapOnRightButton), for: .touchUpInside)

viewFN.addSubview(button1)
viewFN.addSubview(button2)
viewFN.addSubview(button3)

let rightBarButton = UIBarButtonItem(customView: viewFN)

Hope it helps someone. Cheers!