How do I hide/show the right button in the Navigation Bar

Question

I need to hide the right button in the Navigation Bar, then unhide it after the user selects some options.

Unfortunately, the following doesn\'t work:

Answer 1

Swift 2:

Trick!

Hide:

if let btn = self.tabBarController!.navigationItem.rightBarButtonItem {
        btn.enabled = false
        btn.title = ""
}

Show:

if let btn = self.tabBarController!.navigationItem.rightBarButtonItem {
        btn.enabled = true
        btn.title = "ButtonName"
}