IOS TextField Keyboard Problem on Swift [Swift 4.2.1]

keyboardproblem.swift

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
       
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillChange(notification:)), name: UIResponder.keyboardWillShowNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillChange(notification:)), name: UIResponder.keyboardWillHideNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillChange(notification:)), name: UIResponder.keyboardWillChangeFrameNotification, object: nil)
    }
    
    deinit {
        NotificationCenter.default.removeObserver(UIResponder.keyboardWillShowNotification)
        NotificationCenter.default.removeObserver(UIResponder.keyboardWillHideNotification)
        NotificationCenter.default.removeObserver(UIResponder.keyboardWillChangeFrameNotification)
    }
    
    @objc func keyboardWillChange(notification: Notification) {
        
        guard let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue else { return }
        
        if notification.name == UIResponder.keyboardWillChangeFrameNotification || notification.name == UIResponder.keyboardWillShowNotification {
            view.frame.origin.y = -keyboardSize.height
        } else {
            view.frame.origin.y = 0
        }
    }
}