private void btnExport_Click(object sender, RoutedEventArgs e)
 {
     using (FileStream fs = File.Create("D:\\Projects\\BRG\\rawdata.xls"))
     {
         Byte[] info = Encoding.Default.GetBytes(GridViewLineItems.ToHtml(true));
         fs.Write(info, 0, info.Length);
     }
 }
        public void GetLineItems(int InvoiceID)
        {
            try
            {
                List <FBFoodInventoryInfo> items;
                FBFoodInventoryController  controller = new FBFoodInventoryController();

                items = controller.FBInvoice_GetInvoiceLineItems(InvoiceID);

                GridViewLineItems.DataSource = items;
                GridViewLineItems.DataBind();
            }
            catch (Exception ex)
            {
                Exceptions.ProcessModuleLoadException(this, ex);
            }
        }