title: .NET Export large gridview data to excel
body: <p>I'm having trouble using exporting a very large amount of data to excel.  I have a .net 4.0 web page that binds a datatable to a gridview and then attempts to render the gridview in excel.  I have a very large SQL table with over 200 columns that I need to export to excel.  The user is allowed to enter a date range which limits the amount of rows that are returned.  When a date range spans a few across a few months, no data is displayed and the screen freezes. I believe my issue is related to the amount of columns(over 200) that are bound to the gridview.  Is there another way to do this?  How can I successfully export a large amount of data to excel?</p>
  
  <p>I'm using the code below to render the grid -</p>
  
  <pre><code>Response.Clear()
  Response.Buffer = True
  Response.AddHeader("content-disposition","attachment;filename=Test.csv")
  Response.Charset = ""
  Response.Cache.SetCacheability(HttpCacheability.NoCache)
  Response.ContentType = "application/vnd.xls"
  Using sw As New StringWriter()
   Using htw As New HtmlTextWriter(sw)
    Dim gv As As new GridView
    gv.DataSource = dt
    gv.DataBind()
    gv.RenderControl(htw)
    Response.Write(sw.ToString())
    Response.End()
  </code></pre>