Asp.net利用ExcelLibrary输出EXCEL

 public 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.