title: Convert datatable to byte array
body: <p>I want to convert DataTable to byte array in WCF services. After returning value to presentation layer, I want to convert byte array to excel. 
  That is to say; I want to do  below at presentation layer that is user interface side (web site).</p>
  
  <pre><code>Response.Clear();
  Response.ContentType = "application/vnd.ms-excel";
  Response.AppendHeader("Content-Disposition", "attachment; filename=" + fileName + ".xls");
  
  Response.OutputStream.Write(s, 0, s.Length);
  Response.OutputStream.Flush();
  Response.OutputStream.Close();
  Response.Flush();
  Response.Close();
  </code></pre>
  
  <p>I didnot do it. How can I convert datatable to byte array?</p>