UITextField+UIToolbar+toolbarDone.swift

import UIKit

public extension UIToolbar {
    static func toolbarDone(text: String = "Done", target: Any?, action: Selector?) -> UIToolbar {
        let toolbar = UIToolbar()
        toolbar.sizeToFit()
        let doneButton = UIBarButtonItem(title: text, style: .plain, target: target, action: action)
        toolbar.setItems([doneButton], animated: false)
        return toolbar
    }
}

public extension UITextField {
    func addToolbar(text: String = "Done") {
        let toolbar = UIToolbar()
        toolbar.sizeToFit()
        let doneButton = UIBarButtonItem(title: text, style: .plain, target: self, action: #selector(resignFirstResponder))
        let flexibleSpace = UIBarButtonItem(barButtonSystemItem: UIBarButtonItem.SystemItem.flexibleSpace, target: self, action: nil)
        toolbar.setItems([flexibleSpace, doneButton], animated: false)
        self.inputAccessoryView = toolbar
    }
}