Question

If the file name contains accents, it works as expected in Opera, FF, Chrome and IE9.

But in IE8 file type is “unknown file type”, and shows “file” as the file name (actually the last part of the URL).

Does anyone know a workaround? Other than replacing the “special” characters in the file name?

The test code: (file | new project | add controller)

public class FileController : Controller
{
    public ActionResult Index(bool? Accents)
    {
        byte[] content = new byte[] { 1, 2, 3, 4 };

        return File(content, "application/octet-stream", true.Equals(Accents) ? "dsaé.txt" : "dsae.txt");
    }
}

test it like this:
http://localhost/file, and
http://localhost/file?accents=true

Edit => The “solution” for me, if anyone interested:

public class FileContentResultStupidIE : FileContentResult //yeah, maybe i am not totally "politically correct", but still...
{
    public FileContentResultStupidIE(byte[] fileContents, string contentType) : base(fileContents, contentType) { }

    public override void ExecuteResult(ControllerContext context)
    {
        var b = context.HttpContext.Request.Browser;
        if (b != null && b.Browser.Equals("ie", StringComparison.OrdinalIgnoreCase) && b.MajorVersion <= 8)
        {
            context.HttpContext.Response.AppendHeader("Content-Disposition", "attachment; filename=\"" + HttpUtility.UrlPathEncode(base.FileDownloadName) + "\"");
            WriteFile(context.HttpContext.Response);
        }
        else
        {
            base.ExecuteResult(context);
        }
    }
}

Answer 1

Try adding the following line inside your controller action:

Response.HeaderEncoding = Encoding.GetEncoding("iso-8859-1");

You may take a look at the following blog post which discusses those issues. Unfortunately there isn’t a general solution which will work among all browsers.