title: Download excel file using memory stream in C#
body: <p>I have to return file by creating excel workbook from memory stream. I have used Interop, closed.xml, spire.xls but not founding a way to achieve the same.</p>
  <pre><code>    var stream=clsUploadHelper.GetAttachmentFileStream(string.Empty, Filename);
  Workbook book=new Workbook();
  book.worksheet.Add(stream);
                              stream.Position = 0;
                              string xmlString = &quot;attachment;filename=&quot; + Filename;
                              return File(stream, xmlString, Filename);
  </code></pre>
  <p>I am new in that, Please help if possible. Thanks in advance.</p>