title: ASP.NET export to Excel shows html markup in spreadsheet
body: <p>I've tried many articles so far and found nothing that works correctly. The following method produces an excel spreadsheet, but when opened the cells contain html tags and the actual content. Obviously, I don't want  in the spreadsheet...</p>
  
  <pre><code> private static void ExportDataSetToExcel(DataTable dataTable, string filename)
        {
           HttpResponse response = HttpContext.Current.Response;
  
           // first let's clean up the response.object
           response.Clear();
           response.Charset = "";
  
           // set the response mime type for excel
           response.ContentType = "application/vnd.ms-excel";
           response.AddHeader("Content-Disposition", "attachment;filename=\"" + filename + "\"");
  
           // create a string writer
           using(StringWriter sw = new StringWriter())
           {
              using(HtmlTextWriter htw = new HtmlTextWriter(sw))
              {
                 // instantiate a datagrid
                 DataGrid dg = new DataGrid {DataSource = dataTable};
                 dg.DataBind();
                 dg.RenderControl(htw);
                 response.Write(sw.ToString());
                 response.End();
              }
           }
        }
  </code></pre>