private func addNotificationObserver() {

NSNotificationCenter.defaultCenter().addObserver(self, selector:#selector(Class.keyboardWillShow(_:)), name:UIKeyboardWillShowNotification, object:nil)

NSNotificationCenter.defaultCenter().addObserver(self, selector:#selector(Class.keyboardWillHidden(_:)), name:UIKeyboardWillHideNotification, object:nil)

}

@objc private funckeyboardWillShow(notify:NSNotification) {

print("show+++")

}

@objcprivatefunckeyboardWillHidden(notify:NSNotification) {

print("hidden+++")

}