HttpResponse substituting underscores for spaces in file names

Question

When downloading a file with Response.Write spaces in the file name are replaced with underscores, and when the associated application opens, a number in square brackets is appended:

Response.AppendHeader("Content-disposition", "attachment; filename=this is the file.xml");
Response.Write(dr["InfopathDoc"]);

This results in this file name in the associated application:

this_is_the_file[1].xml

How can I get rid of the underscores and why do I get the [1] ?

Thanks

Answer 1

Found the solution for this problem here

http://dotnetslackers.com/Community/blogs/kaushalparik/archive/2009/05/06/file-download-problem-filename-with-spaces-truncated-in-ff-and-replaced-by-underscore-in-ie.aspx

To solve problem for FF, add quotes around the filename as

Response.AddHeader("Content-Disposition", "attachment; filename=\"" + filename + "\"");

And for IE, replace spaces with '%20'

filename = toDownload.Name.Replace(" ", "%20");

Answer 2

If anyone is still interested:

This kind of file name rewriting is done by the browser only as you can see when inspecting the received HTTP response with an appropriate tool, independent of the browser used. IE first downloads the requested file into its "Temporary Internet Files" folder system (which is not just one, but this is another topic), and for this purpose the file receives a new name, making best match to the "Content-Disposition" suggestion from the HTTP response. But if an equally named file is already present in the actual "Temporary Internet Files" folder actually used for this file, its name is extended by a sequenced number in brackets, like "[2]". Because every new HTTP request causes the IE cache mechanism to newly compute the actual cache folder, and the next cache folder chosen may not yet contain a file with that name, the number may seem to vanish at the next download of a file or resource with the same name.

If a downloaded file is stored somewhere, the originally suggested file name is used again usually, depending on the IE version. Some versions and patch levels seem to use the cache folder file name instead :-(

The problem starts to become annoying when the browser hands out a downloaded file to a chosen or automatically selected application. In this case the application is called to open the file directly from the cache, which is bad for at least 2 reasons:

(1) The file name will be the name of the file in the cache folder, not the suggested name. This may even strip the extension, which will confuse some applications even if they have been chosen for handling the file correctly.

(2) If an internet newbie user downloads and opens a file for editing and then simply presses the "Save" button of the application, the file is simply saved into the IE cache folder, and no user of this kind will ever find this file again. These are things which can turn people really angry and desperate...