Unable to evaluate expression… on web page

Question

Related to this question: Unable to evaluate expression because the code is optimized or a native frame is on top of the call stack

I am currently seeing this in my

Answer 1

The code is fine. When you do Response.End() you get a ThreadAbortException:

http://support.microsoft.com/kb/312629/EN-US/

Some people consider Response.End() too drastic though:

Is Response.End() considered harmful?

I would suggest handling this specific exception (since you know you are going to get it), and moving the reponse.End() (like mellamokb suggested):

        HttpResponse response = HttpContext.Current.Response;
        try
        {
            DataSet dataSet = new DataSet();
            DataTable table = new DataTable();

            dataSet.Tables.Add(table);

            response.Clear();
            response.Charset = "";

            response.ContentType = "application/vnd.ms-excel";
            response.AddHeader("Content-Disposition", "attachment;filename=\"ExcelFile.xls\"");

            using (StringWriter stringWriter = new StringWriter())
            using (HtmlTextWriter htmlTextWriter = new HtmlTextWriter(stringWriter))
            {
                DataGrid dataGrid = new DataGrid { DataSource = dataSet.Tables[0] };

                dataGrid.DataBind();
                dataGrid.RenderControl(htmlTextWriter);

                response.Write(stringWriter.ToString());

            }
            response.End();
        }
        catch (ThreadAbortException ex)
        {
            //Log some trace info here
        }