public string GetCsv(string[] columns, List<object>[] data)
    {
        StringBuilder CsvData = new StringBuilder();

        //add column headers
        string[] s = new string[Columns.Count];
        for (Int32 j = 0; j < Columns.Count; j++)
        {
            s[j] = columns[j];
            if (s[j].Contains(""")) //replace " with ""
                s[j].Replace(""", """");
            if (s[j].Contains(""") || s[j].Contains(" ")) //add "'s around any string with space or "
                s[j] = """ + s[j] + """;
        }
        CsvData.AppendLine(string.Join(",", s));

        //add rows
        foreach (var row in data)
        {
            for (int j = 0; j < Columns.Count; j++)
            {
                s[j] = row[j] == null ? "" : row[j].ToString();
                if (s[j].Contains(""")) //replace " with ""
                    s[j].Replace(""", """");
                if (s[j].Contains(""") || s[j].Contains(" ")) //add "'s around any string with space or "
                    s[j] = """ + s[j] + """;
            }
            CsvData.AppendLine(string.Join(",", s));
        }

        return CsvData.ToString();

    }