DataTable convert into Csv and push to the browser

gistfile1.cs

 public class DataTableToCsv
    {
        public void Generate(DataTable dt, string fileName)
        {
            var sb = new StringBuilder();

            IEnumerable<string> columnNames = dt.Columns.Cast<DataColumn>().
                                              Select(column => column.ColumnName);
            sb.AppendLine(string.Join(",", columnNames));

            foreach (DataRow row in dt.Rows)
            {
                IEnumerable<string> fields = row.ItemArray.Select(field =>
                  string.Concat("\"", field.ToString().Replace("\"", "\"\""), "\""));
                sb.AppendLine(string.Join(",", fields));
            }

            PushCsvToBrowser(sb, fileName);
        }

        private void PushCsvToBrowser(StringBuilder sb, string fileName)
        {
            string attachment = "attachment; filename=" + fileName;
            HttpContext.Current.Response.Clear();
            HttpContext.Current.Response.ClearHeaders();
            HttpContext.Current.Response.ClearContent();
            HttpContext.Current.Response.AddHeader("content-disposition", attachment);
            HttpContext.Current.Response.ContentType = "text/csv";
            HttpContext.Current.Response.AddHeader("Pragma", "public");

            HttpContext.Current.Response.Write(sb.ToString());
            HttpContext.Current.Response.End();
        }
    }