Why are .docx files being corrupted when downloading from an ASP.NET page?

Question

I have this following code for bringing page attachments to the user:

private void GetFile(string package, string filename)
{
    var stream = new MemoryStre         


        

Answer 1

If you use the approach above which uses response.Close(), Download managers such as IE10 will say 'cannot download file' because the byte lengths do not match the headers. See the documentation. Do NOT use response.Close. EVER. However, using the CompeteRequest verb alone does not shut off the writing of bytes to the ouput stream so XML based applications such as WORD 2007 will see the docx as corrupted. In this case, break the rule to NEVER use Response.End. The following code solves both problems. Your results may vary.

        '*** transfer package file memory buffer to output stream
        Response.ClearContent()
        Response.ClearHeaders()
        Response.AddHeader("content-disposition", "attachment; filename=" + NewDocFileName)
        Me.Response.ContentType = "application/vnd.ms-word.document.12"
        Response.ContentEncoding = System.Text.Encoding.UTF8
        strDocument.Position = 0
        strDocument.WriteTo(Response.OutputStream)
        strDocument.Close()
        Response.Flush()
        'See documentation at http://blogs.msdn.com/b/aspnetue/archive/2010/05/25/response-end-response-close-and-how-customer-feedback-helps-us-improve-msdn-documentation.aspx
        HttpContext.Current.ApplicationInstance.CompleteRequest() 'This is the preferred method
        'Response.Close() 'BAD pattern. Do not use this approach, will cause 'cannot download file' in IE10 and other download managers that compare content-Header to actual byte count
        Response.End() 'BAD Pattern as well. However, CompleteRequest does not terminate sending bytes, so Word or other XML based appns will see the file as corrupted. So use this to solve it.

@Cesar: you are using response.Close--> can you try it with IE 10? bet it doesn't work (byte counts don't match)