UITextField代理方法

extension CreatePdfViewController: UITextFieldDelegate{
    func textFieldDidBeginEditing(_ textView:UITextField) {
        UIView.animate(withDuration: 0.4, animations: {
            self.view.frame.origin.y = -180
        })
    }
  func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        textField.resignFirstResponder()
        return false
    }
}