问如何在键盘上方添加按钮

EN

class ViewController : UIViewController {

@IBOutlet weak var textField: UITextField!
override func viewDidLoad() {
    super.viewDidLoad()

    textField.inputAccessoryView = Bundle.main.loadNibNamed("CustomAccessoryView", owner: self, options: nil)?.first as! UIView?

import UIKit

class CustomAccessoryView: UIView {

    @IBAction func clickLoveButton(_ sender: UIButton) {

        print("Love button clicked")
    }
}

import UIKit

class ViewController: UIViewController {
    // your `UITextfield` instance
    // Don't forget to attach it from the IB or create it programmaticly
    @IBOutlet weak var textField: UITextField!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Assign the delegate to self
        textField.delegate = self
    }
}

// MARK: Create extension to conform to UITextfieldDelegate
extension ViewController: UITextFieldDelegate {
    func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {
        setupTextFieldsAccessoryView()
        return true
    }

    func setupTextFieldsAccessoryView() {
        guard textField.inputAccessoryView == nil else {
            print("textfields accessory view already set up")
            return
        }

        // Create toolBar
        let toolBar: UIToolbar = UIToolbar(frame:CGRect(x: 0, y: 0, width: UIScreen.main.bounds.size.width, height: 44))
        toolBar.barStyle = UIBarStyle.black
        toolBar.isTranslucent = false

        // Add buttons as `UIBarButtonItem` to toolbar
        // First add some space to the left hand side, so your button is not on the edge of the screen
        let flexsibleSpace: UIBarButtonItem = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.flexibleSpace, target: nil, action: nil) // flexible space to add left end side

        // Create your first visible button
        let doneButton: UIBarButtonItem = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.done, target: self, action: #selector(didPressDoneButton))
        // Note, that we declared the `didPressDoneButton` to be called, when Done button has been pressed
        toolBar.items = [flexsibleSpace, doneButton]

        // Assing toolbar as inputAccessoryView
        textField.inputAccessoryView = toolBar
    }

    func didPressDoneButton(button: UIButton) {
        // Button has been pressed
        // Process the containment of the textfield or whatever

        // Hide keyboard
        textField.resignFirstResponder()
    }
}

 override func viewDidLoad() {
    super.viewDidLoad()
      let button = UIButton(frame: CGRect(x: 0, y: 0, width: view.frame.size.width, height: 60))
      button.backgroundColor = UIColor.blue
      button.setTitle("NEXT", for: .normal)
      button.setTitleColor(UIColor.white, for: .normal)
      button.addTarget(self, action: #selector(self. yourButton), for: .touchUpInside)
      numtextField.inputAccessoryView = button

 }

 @objc func nextButton()
 {
      print("do something")
 }