private void btn_exit_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                XmlDataService XmlDataService = new XmlDataService(AppConfig.dataFilePath);
                XmlDataService.WriteAll(_characters);
            }
            catch (Exception)
            {
                throw;
            }

            this.Close();
        }
        private void ReadFromXMLToDataGrid()
        {
            string dataFilePath = AppConfig.dataFilePath;

            XmlDataService dataService = new XmlDataService(dataFilePath);

            _characters = dataService.ReadAll();

            var bindingList = new BindingList <Character>(_characters);
            var source      = new DataSet();

            source.ReadXml(dataFilePath);
            dataGridFF.ItemsSource = source.Tables[0].DefaultView;
        }