#region NPOI导出Excel2007到xlsx
        /// <summary>
        /// 导出excel到xlsx
        /// </summary>
        /// <param name="dt">datatable数据源</param>
        /// <param name="strHeaderText">表头</param>
        /// <param name="columnNames">列头</param>
        /// <returns></returns>
        private static MemoryStream ExportXlsx(DataTable dt, string strHeaderText, string[] columnNames)
        {
            if (columnNames != null && columnNames.Length != dt.Columns.Count)
            {
                throw new ArgumentException("参数不正确:columnNames,数组元素的个数需要和数据源列的数量相同!");
            }

            XSSFWorkbook workbook = new XSSFWorkbook();
            ISheet sheet = null;

            string sheetName = "Sheet1";
            if (!string.IsNullOrEmpty(dt.TableName))
            {
                sheetName = dt.TableName;
            }
            sheet = workbook.CreateSheet(sheetName);
            int rowIndex = 0;

            #region 表头及样式
            {
                IRow headerRow = sheet.CreateRow(0);
                headerRow.HeightInPoints = 25;
                headerRow.CreateCell(0).SetCellValue(strHeaderText);

                ICellStyle headStyle = workbook.CreateCellStyle();
                headStyle.Alignment = HorizontalAlignment.Center;
                IFont font = workbook.CreateFont();
                font.FontHeightInPoints = 20;
                font.Boldweight = 700;
                headStyle.SetFont(font);
                headerRow.GetCell(0).CellStyle = headStyle;
                sheet.AddMergedRegion(new CellRangeAddress(0, 0, 0, dt.Columns.Count - 1));
            }
            #endregion

            #region 列头及样式
            {
                XSSFRow headerRow = (XSSFRow)sheet.CreateRow(1);

                ICellStyle headStyle = workbook.CreateCellStyle();
                headStyle.Alignment = HorizontalAlignment.Center;
                IFont font = workbook.CreateFont();
                font.FontHeightInPoints = 10;
                font.Boldweight = 700;
                headStyle.SetFont(font);

                foreach (DataColumn column in dt.Columns)
                {
                    headerRow.CreateCell(column.Ordinal).SetCellValue(columnNames[rowIndex]);
                    headerRow.GetCell(column.Ordinal).CellStyle = headStyle;
                    rowIndex++;
                }
            }
            #endregion

            #region 填充内容
            rowIndex = 1;
            foreach (DataRow row in dt.Rows)
            {
                rowIndex++;
                XSSFRow dataRow = (XSSFRow)sheet.CreateRow(rowIndex);
                foreach (DataColumn column in dt.Columns)
                {
                    string drValue =http://www.mamicode.com/ row[column].ToString();
                    dataRow.CreateCell(column.Ordinal).SetCellValue(drValue);
                }
            }
            #endregion


            MemoryStream ms = new MemoryStream();

            workbook.Write(ms);
            ms.Flush();

            return ms;
        }
        /// <summary>
        /// web导出
        /// </summary>
        /// <param name="dt">数据源</param>
        /// <param name="strFileName">表头</param>
        /// <param name="columnNames">列头</param>
        public static void ExportXlsxByWeb(DataTable dt, string strFileName, string[] columnNames)
        {
            HttpContext curContext = HttpContext.Current;
            MemoryStream ms = ExportXlsx(dt, strFileName, columnNames);
            curContext.Response.AppendHeader("Content-Disposition",
                "attachment;filename=" + HttpUtility.UrlEncode(strFileName + DateTime.Now.ToString("yyyyMMddhhmmssfff"), Encoding.UTF8) + ".xlsx");
            curContext.Response.AddHeader("Content-Length", ms.ToArray().Length.ToString());
            curContext.Response.ContentEncoding = Encoding.UTF8;
            curContext.Response.BinaryWrite(ms.ToArray());
            ms.Close();
            ms.Dispose();
            curContext.Response.End();
        }
        
        #endregion

 protected void lbtnExportExcel_Click(object sender, EventArgs e)
        {
            try
            {
                DataSet dsData = GetData();
                if (dsData != null && dsData.Tables[0].Rows.Count > 0)
                {
                    string headerText = "excel文件名";
                    DataTable tab = dsData.Tables[0];
                    bool b = tab.Columns.Contains("新增列名");
                    if (!b)
                    {
                        tab.Columns.Add("新增列名", Type.GetType("System.String"));
                    }
                              
                    foreach (DataRow dr in dsData.Tables[0].Rows)
                    {                 
                        
                        dr["ServiceAreaName"] = "";  //调用方法进行新列的赋值
                    }
//表头和列头
                    string[] Colums = { "ProductName", "PhysicalCode", "FLgsBar", "PromoterMobile", "Name", "ServiceAreaName", "IntegralNum", "IntegralTime" };
                    string[] ColumNames = { Resources.Admin.Lable_GoodName, Resources.Admin.Lable_PromoterIntegralCode, Resources.Admin.Label_LogisticsCode, Resources.Admin.Lable_MobilePhone, Resources.Admin.Lable_FullName, Resources.Admin.Lable_Area, Resources.Admin.Lable_IntegralValue, Resources.Admin.Lable_IntegralTime };

NPOIHelper.ExportXlsxByWeb(GetTableData(Colums, tab), headerText, ColumNames);
                }
                else
                {
                    Common.MessageBox.ShowFailTip(this, Resources.Admin.Tip_Fail_Empty_Search);
                }
            }
            catch (Exception ex)
            {
                LogHelp.AddErrorLog("ERROR: ", ex.StackTrace, this.Request);
            }
        }

protected DataTable GetTableData(string[] Columns, DataTable Data)
        {
            DataTable tab = new DataTable();
            foreach (string col in Columns)
            {
                tab.Columns.Add(col);
            }
            foreach (DataRow dr in Data.Rows)
            {
                DataRow drt = tab.NewRow();
                foreach (string col in Columns)
                {
                    drt[col] = dr[col];
                }
                tab.Rows.Add(drt);
            }
            return tab;
        }