Wsrtjtyk

I've been working on getting the height of the keyboard in swift 4.2. I've been using the Notification Center to call a function when the keyboard shows which accepts a notification as a param, which I think is pretty standard? Here I want to calculate the height. However the notification object is missing data and I can't calculate the height.

NSConcreteNotification 0x16e43a710 {

    name = UIKeyboardDidShowNotification; userInfo = {

       UIKeyboardAnimationCurveUserInfoKey = 7;

       UIKeyboardAnimationDurationUserInfoKey = "0.25";

       UIKeyboardBoundsUserInfoKey = "NSRect: {{0, 0}, {0, 0}}";

       UIKeyboardCenterBeginUserInfoKey = "NSPoint: {0, 0}";

       UIKeyboardCenterEndUserInfoKey = "NSPoint: {0, 0}";

       UIKeyboardFrameBeginUserInfoKey = "NSRect: {{0, 0}, {0, 0}}";

       UIKeyboardFrameEndUserInfoKey = "NSRect: {{0, 0}, {0, 0}}";

       UIKeyboardIsLocalUserInfoKey = 1;

    }

}

I call a commonInit function from my init method which sets up the methods to call:

private func commonInit() {

    NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow(notification:)), name: UIResponder.keyboardDidShowNotification, object: nil)

    NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)



}

KeyboardWillShow Function

@objc private func keyboardWillShow(notification:NSNotification) {



    let userInfo = notification.userInfo! as NSDictionary

    let keyboardFrame = userInfo.value(forKey: UIResponder.keyboardFrameEndUserInfoKey) as! NSValue

    let keyboardRectangle = keyboardFrame.cgRectValue

    let keyboardHeight = keyboardRectangle.height



    print(keyboardHeight)

}

Is there something missing to get the notification data?

That's what I always use:

func addObservers() {

        NotificationCenter.default.addObserver(forName: UIResponder.keyboardWillShowNotification,

                                               object: nil,

                                               queue: nil) { [weak self] (notification) in

                                                self?.keyboardWillShow(notification: notification as NSNotification)

        }



        NotificationCenter.default.addObserver(forName: UIResponder.keyboardWillHideNotification,

                                               object: nil,

                                               queue: nil) {  [weak self] (notification) in

                                                self?.keyboardWillHide(notification: notification as NSNotification)

        }



    }





func keyboardWillShow(notification: NSNotification) {

        if let userInfo = notification.userInfo {

            let keyboardHeight = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as AnyObject).cgRectValue.size.height

     }

     //... do your stuff...

 }