UITextFieldのキーボードに下記のようなUIToolbarを実装してみたいと思います。二個目の実装は参照を参考に改造をしたものです。安易に実装が出来て非常に便利だと思ったので書き残しておきます。

元ネタ

import UIKit

class ViewController: UIViewController {


    @IBOutlet weak var addressField: UITextField!


    override func viewDidLoad() {
        super.viewDidLoad()
        addToolBar(textField: addressField)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}

extension UIViewController: UITextFieldDelegate{
    func addToolBar(textField: UITextField){
        let toolBar = UIToolbar()
        toolBar.barStyle = UIBarStyle.default
        toolBar.isTranslucent = true
        toolBar.tintColor = UIColor(red: 76/255, green: 217/255, blue: 100/255, alpha: 1)
        let doneButton = UIBarButtonItem(title: "Done", style: UIBarButtonItemStyle.done, target: self, action: #selector(UIViewController.donePressed))
        let cancelButton = UIBarButtonItem(title: "Cancel", style: UIBarButtonItemStyle.plain, target: self, action: #selector(UIViewController.cancelPressed))
        let spaceButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.flexibleSpace, target: nil, action: nil)
        toolBar.setItems([cancelButton, spaceButton, doneButton], animated: false)
        toolBar.isUserInteractionEnabled = true
        toolBar.sizeToFit()

        textField.delegate = self
        textField.inputAccessoryView = toolBar
    }
    func donePressed(){
        view.endEditing(true)
    }
    func cancelPressed(){
        view.endEditing(true) // or do something
    }
}

実装

import UIKit

class ViewController: UIViewController {


    @IBOutlet weak var addressField: UITextField!


    override func viewDidLoad() {
        super.viewDidLoad()
        addToolBar(textField: addressField)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}

extension UIViewController: UITextFieldDelegate{



    func addToolBar(textField: UITextField){
        let toolBar = UIToolbar()
        toolBar.barStyle = UIBarStyle.default
        toolBar.isTranslucent = true
        toolBar.tintColor = UIColor(red: 76/255, green: 217/255, blue: 100/255, alpha: 1)


        let JayZButton = UIBarButtonItem(title: "JayZ", style: UIBarButtonItemStyle.done, target: self, action: #selector(UIViewController.RapGod))

        let BeyoncéButton = UIBarButtonItem(title: "Beyoncé", style: UIBarButtonItemStyle.plain, target: self, action: #selector(UIViewController.JayZwife))


        let DrakeButton = UIBarButtonItem(title: "Drake", style: UIBarButtonItemStyle.plain, target: self, action: #selector(UIViewController.bestIeverHad))

        let RihannaButton = UIBarButtonItem(title: "Rihanna", style: UIBarButtonItemStyle.plain, target: self, action: #selector(UIViewController.DrakeLoveRihanna))

        //let spaceButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.flexibleSpace, target: nil, action: nil)


        toolBar.setItems([JayZButton, BeyoncéButton, DrakeButton, RihannaButton], animated: false)
        toolBar.isUserInteractionEnabled = true
        toolBar.sizeToFit()

        textField.delegate = self
        textField.inputAccessoryView = toolBar
    }

    func RapGod(){
//        view.endEditing(true)
        print("ラップの神様")
    }

    func JayZwife(){
//        view.endEditing(true)
        print("JayZの嫁")
    }

    func bestIeverHad(){
        print("bestIeverHad")
    }

    func DrakeLoveRihanna(){
        print("ドレイクはリアーナが大好き")
    }
}

参考

Add UIToolBar to all keyboards (swift)

off.tokyo｜スキルキャリアもっと輝け

UITextFieldのキーボードにUIToolbarを追加する

元ネタ

実装

実装

参考