How to HTML encode a csv export

Question

I get

 Quattrode® 

From a string that is HTML encoded as

Quattrode® 

when viewing inside Excel 2007.

Routine

        Response.Clear();
        Response.Buffer = true;

        Response.ContentType = "text/comma-separated-values";
        Response.AddHeader("Content-Disposition", "attachment;filename=\"Expired.csv\"");

        Response.RedirectLocation = "export.csv";

        Response.Charset = "";
        //Response.Charset = "UTF-8";//this does not work either.
        EnableViewState = false;

        ExportUtility util = new ExportUtility();

        Response.Write(util.DataGridToCSV(gridViewExport, ","));

Basically DataGridToCSV() uses HttpUtility.HtmlDecode(stringBuilder.ToString()); and I can use visual studio's text visualizer and see the string looks correct (Quattrode®).

So something in the Response procedure or in Excel's interpretation of the file is not correct. Any idea how to fix?

---

UPDATE
Turns out that this is not interpreted properly in Excel or WordPad. I open it up in Notepad and the symbol shows up properly.

Answer 1

I found the answer here https://stackoverflow.com/a/3300854/150342 and here https://stackoverflow.com/a/6460488/150342 Then put together this code:

    public static void WriteCSVToResponse(string csv, string filename)
    {
        HttpResponse response = HttpContext.Current.Response;
        response.Clear();
        response.ClearHeaders();
        response.ClearContent();
        response.ContentType = "text/csv";
        response.AddHeader("content-disposition", "attachment; filename=" + filename);
        response.ContentEncoding = Encoding.UTF8;

        byte[] BOM = new byte[] { 0xef, 0xbb, 0xbf };
        response.BinaryWrite(BOM);//write the BOM first
        response.BinaryWrite(Encoding.UTF8.GetBytes(csv));
        response.Flush();
        response.End();
    }

Answer 2

也试试这个

Response.ContentEncoding = Encoding.UTF32;

Answer 3

Response.Charset = "";

Try using something like UTF-8