Html – Force to open “Save As…” popup open at text link click for PDF in HTML

Part of the problem is that the relevant RFC 2183 doesn't really state what to do with a disposition type of "inline" and a filename.

Also, as far as I can tell, the only UA that actually uses the filename for type=inline is Firefox (see test case).

Finally, it's not obvious that the plugin API actually makes that information available (maybe someboy familiar with the API can elaborate).

That being said, I have sent a pointer to this question to an Adobe person; maybe the right people will have a look.

Related: see attempt to clarify Content-Disposition in HTTP in draft-reschke-rfc2183-in-http -- this is early work in progress, feedback appreciated.

Update: I have added a test case, which seems to indicate that the Acrobat reader plugin doesn't use the response headers (in Firefox), although the plugin API provides access to them.

public ActionResult Download()
{
    var document = ...
    var cd = new System.Net.Mime.ContentDisposition
    {
        // for example foo.bak
        FileName = document.FileName, 

        // always prompt the user for downloading, set to true if you want 
        // the browser to try to show the file inline
        Inline = false, 
    };
    Response.AppendHeader("Content-Disposition", cd.ToString());
    return File(document.Data, document.ContentType);
}

NOTE: This example code above fails to properly account for international characters in the filename. See RFC6266 for the relevant standardization. I believe recent versions of ASP.Net MVC's File() method and the ContentDispositionHeaderValue class properly accounts for this. - Oskar 2016-02-25