My view runs outside the screen and doesn't shift back down

Question

I tried to implement a Notification that alerts the view that the Keyboard will appear and should shift upwards with the keyboards height.

func subscribeToKeyboardNotifications() {
    NotificationCenter.default.addObserver(self, selector: #selector(KeyboardWillShow(_:)), name: .UIKeyboardWillShow, object: nil)
}

Here is the KeyboardWillShow method body:

@objc func KeyboardWillShow(_ notification: Notification) {
    view.frame.origin.y -= getKeyBoardHeight(notification)
}

and the getKeyBoardHeight function:

func getKeyBoardHeight(_ notification: Notification) -> CGFloat {
    let userinfo = notification.userInfo
    let keyboardsize = userinfo![UIKeyboardFrameEndUserInfoKey] as! NSValue

    return keyboardsize.cgRectValue.height
}

Why does my app shift completely out of view and when I toggle the keyboard on in the simulator?

Answer 1

These are the methods I use on a regular basis that work, I think your issue is with using -= getKeyboardHeight , try the code in my keyboardWillShow method below

class VC: UIViewController {

    func subscribeToKeyboardNotifications() {
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: .UIKeyboardWillShow, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: .UIKeyboardWillHide, object: nil)
    }

    func unsubscribeFromKeyboardNotifications() {
        NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillShow, object: nil)
        NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillHide, object: nil)
    }

    @objc func keyboardWillHide(notification: NSNotification) {
        view.frame.origin.y = 0
    }

    @objc func keyboardWillShow(notification: NSNotification) {
        view.frame.origin.y = -getKeyboardHeight(notification: notification)
    }

    func getKeyboardHeight(notification: NSNotification) -> CGFloat {
        let userInfo = notification.userInfo
        let keyboardSize = userInfo![UIKeyboardFrameEndUserInfoKey] as! NSValue
        return keyboardSize.cgRectValue.height
    }

}