iOS KeyboardBindView extension

KeyboardBindView.swift

import Foundation
import UIKit

extension UIView {
    func bindToKeyboard() {
        NotificationCenter.default.addObserver(self, selector: #selector(UIView.keyboardWillChange(_:)), name: NSNotification.Name.UIKeyboardWillChangeFrame, object: nil)
    }
    
    @objc func keyboardWillChange(_ notification: NSNotification) {
        let duration = notification.userInfo![UIKeyboardAnimationDurationUserInfoKey] as! Double
        let curve = notification.userInfo![UIKeyboardAnimationCurveUserInfoKey] as! UInt
        let curFrame = (notification.userInfo![UIKeyboardFrameBeginUserInfoKey] as! NSValue).cgRectValue
        let targetFrame = (notification.userInfo![UIKeyboardFrameEndUserInfoKey] as! NSValue).cgRectValue
        let deltaY = targetFrame.origin.y - curFrame.origin.y
        
        UIView.animateKeyframes(withDuration: duration, delay: 0.0, options: UIViewKeyframeAnimationOptions(rawValue: curve), animations: {
            self.frame.origin.y += deltaY
        }) { (true) in
            self.layoutIfNeeded()
        }
    }
}