MIME-Type for Excel XML (ASP.NET 3.5)

Question

I use CarlosAG-Dll which creates a XML-Excel-file for me (inside a MemoryStream).

Response.ContentType = \"application/vnd.ms-excel\";
Response.AppendHeader(         


        

Answer 1

If your document is an Excel Xml 2003 document, you should use the text/xml content type.

Response.ContentType = "text/xml";

Do not specifiy content-disposition.

This technichs works great with Handler, not with WebForm.

Answer 2

The security warning is NOT about the MIME type - it is a client-side security setting you can't disable from the server side !

Another point - change Response.AppendHeader("content-disposition", "myfile.xml"); to:

Response.AppendHeader("content-disposition", "attachment; filename=myfile.xlsx");

OR

Response.AppendHeader("content-disposition", "inline; filename=myfile.xlsx");

For reference see http://www.ietf.org/rfc/rfc2183.txt

EDIT - as per comment:

IF the format is not XLSX (Excel 2007 and up) then use myfile.xls in the above code.

Answer 3

Use like this

Response.ContentType = "application/vnd.ms-excel";

Response.AppendHeader("content-disposition", "attachment; filename=myfile.xls");

For Excel 2007 and above the MIME type differs

Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";

Response.AppendHeader("content-disposition", "attachment; filename=myfile.xlsx");

See list of MIME types

Office 2007 File Format MIME Types

EDIT:

If the content is not a native Excel file format, but is instead a text based format (such as CSV, TXT, XML), then the web site can add the following HTTP header to their GET response to tell IE to use an alternate name, and in the name you can set the extension to the right content type:

Response.AddHeader "Content-Disposition", "Attachment;Filename=myfile.csv"

For more details see this link