UIBarButtonItem is not working swift 3.0 - ios

Question

I have a Navigation controller and I'm trying to put a button on the right of navigation bar but I can't handle the tap action. I'm declaring the UIBarButtonItem like this
let navigationButton = UIBarButtonItem.init(title: "Logout", style: .done, target: self, action: #selector(RestaurantsListViewController.logoutAction))
I'm adding the button on the viewDidLoad func
override func viewDidLoad() {
super.viewDidLoad()
self.navigationItem.rightBarButtonItem = navigationButton
}
and the function that I'm trying to use to handle the tap event is this
func logoutAction(sender: AnyObject?){
print("Logout")
}
but when I press the button, the message is not printed in console.

Answer 1

Try this:
override func viewDidLoad() {
super.viewDidLoad()
self.navigationItem.rightBarButtonItem = UIBarButtonItem(title: "ButtonName", style: .done, target: self, action: #selector(YourViewController.yourAction))
}

Answer 2

let okbtn = UIBarButtonItem(title: "Done", style: UIBarButtonItemStyle.plain, target: self, action: #selector(ViewController.logoutAction))
Try This
otherwise You need to replace func like
func logoutAction()
{
print("logout")
}

Answer 3

The issue here is when you create navigationButton as a class property, it gets initialized before self is initialized. So self doesn't exist yet when you pass it in as the target of the button.
There are a couple ways to fix it, including the answer by #Mannopson where you initialize the button inside the viewDidLoad, which ensures that self has already been created.
Another way to solve this issue is to declare navigationButton to be a lazy var:
lazy var navigationButton = UIBarButtonItem.init(title: "Logout", style: .done, target: self, action: #selector(RestaurantsListViewController.logoutAction))
The lazy var ensures that the property only gets initialized when the property gets accessed (hence it being a lazy initialization). Since the first time it is accessed happens in viewDidLoad, we can also be sure that self has been created. Hope this gives you more context!