DataTable 导出excel 2003 采用ExcelLibrary

 public static   class ExportExcel
    {
        public static void DataTable2Excel(string attachName, DataTable tab)
        {
            string file = HttpContext.Current.Server.MapPath("/uploads/export/" + Guid.NewGuid().ToString() + ".xls");
            Workbook workbook = new Workbook();
            Worksheet worksheet = new Worksheet("Sheet1");
            //构建表头
            for (int col = 0; col < tab.Columns.Count; col++)
            {
                worksheet.Cells[0, col] = new Cell(tab.Columns[col].ColumnName);
            }

            for (int rowIndex = 0; rowIndex < tab.Rows.Count; rowIndex++)
            {
                for (int colIndex = 0; colIndex < tab.Columns.Count; colIndex++)
                {
                    worksheet.Cells[rowIndex + 1, colIndex] = new Cell(tab.Rows[rowIndex][colIndex].ToString());
                }
            }
            //设置默认宽度
            if (worksheet.Cells.LastRowIndex > 1)
            {
                for (int n = 0; n < tab.Columns.Count; n++)
                {
                    if (worksheet.Cells[1, n].Value.ToString().Length >= 50)
                        worksheet.Cells.ColumnWidth[(ushort)n] = 10000;
                    else if (worksheet.Cells[1, n].Value.ToString().Length >= 10)
                        worksheet.Cells.ColumnWidth[(ushort)n] = (ushort)(worksheet.Cells[1, n].Value.ToString().Length * 300);
                    else
                        worksheet.Cells.ColumnWidth[(ushort)n] = 3000;
                }
            }
            else
                worksheet.Cells.ColumnWidth[0, (ushort)(tab.Columns.Count - 1)] = 3000;

            workbook.Worksheets.Add(worksheet);
            workbook.Save(file);
            FileInfo info = new FileInfo(file);
            long size = 0;
            if (info.Exists)
                size = info.Length;
            HttpContext.Current.Response.AddHeader("content-type", "application/x-msdownload;");
            HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(attachName + ".xls"));
            HttpContext.Current.Response.AddHeader("content-length", size.ToString());
            HttpContext.Current.Response.WriteFile(file, 0, size);

        }
    }