完成第三步：通过三层调用重新实现XML序列化

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Collections.Generic;
using System.ComponentModel;
using System.Xml;
using System.Data.SqlClient;
using System.IO;
using System.Xml.Serialization;
using System.Diagnostics;
using System.Text;
using DataAccess.PO;
using BusinessFacade;

public partial class DataManagement_IndicatorConfiguration : System.Web.UI.Page
{

    protected void Page_Load(object sender, EventArgs e)
    {  
    }


    protected void ShowButton_Click(object sender, EventArgs e)
    {
        try
        {
            //文本框 关键字匹配
            string keyWord = KeyWordTextBox.Text;
            /**////从EWS库取指标
            StringBuilder indiCodes = new StringBuilder();
            if (IndicatorMultiSelectControl1.SelectedIndicatorList != null)
            {
                if (string.IsNullOrEmpty(keyWord))
                {
                    foreach (Indicator indi in IndicatorMultiSelectControl1.SelectedIndicatorList)
                    {
                        indiCodes.Append("'" + indi.IndicatorCode + "',");//加逗号是因为参数里有逗号分隔符
                    }
                }
                else
                {
                    foreach (Indicator indi in IndicatorMultiSelectControl1.SelectedIndicatorList)
                    {
                        if(indi.DisplayName.Contains(keyWord))
                            indiCodes.Append("'" + indi.IndicatorCode + "',");//加逗号是因为参数里有逗号分隔符
                    }

                }
            }
            if (indiCodes == null || indiCodes.Length == 0)
                return;
            indiCodes.Remove(indiCodes.Length - 1, 1);//去掉加上的逗号
            string filter = "IndicatorID  in ( " + indiCodes.ToString() + " )";

            /**////从PBC库中取出数据  
            PBCIntegrationManager manager = new PBCIntegrationManager();
            List<Import_MonthBase> monthbase = new List<Import_MonthBase>();
            monthbase = manager.GetEntityList(filter);
            Session["PBCmonthbase"] = monthbase;

            DataTable dt = PBCAnalyzer.GetIndicatorMonthBase(monthbase, IndicatorMultiSelectControl1.SelectedIndicatorList);
                

            //DataSet ds = manager.GetList(filter);

            //DataTable table = new DataTable();
            //DataColumn id = new DataColumn("指标名称");
            //table.Columns.Add(id);

            /**////显示数据
            ImportGridView.DataSource = dt;
            ImportGridView.DataBind();

           // ///从PBC库中取出数据                                   
           // SqlConnection PBCconn = new SqlConnection("server=localhost;Integrated Security=SSPI;database=PBCDataBaseTest;");
           // PBCconn.Open();
           // SqlCommand PBCCommand = PBCconn.CreateCommand();
           // PBCCommand.CommandText = "SELECT * FROM MonthBase where IndicatorID  in ( " + indiCodes.ToString() + " )";//将参数放进SQL语句中
           /**///// PBCCommand.CreateParameter()  //这方法也能将参数放进SQL语句中
           // SqlDataReader PBCdr = PBCCommand.ExecuteReader();

           // ///将数据放入GridView中
           // if (PBCdr.Read())
           // {
           //     nodataLabel.Text = " ";//清空错误数据
           //     ImportGridView.DataSource = PBCdr;
           //     ImportGridView.DataBind();
           // }
           // else
           // {
           //     nodataLabel.Text = "抱歉，PBC库无对应数据！";
           //     return;
           // }
           // PBCdr.Close();
           // PBCconn.Close();


        }
        catch (Exception ex)
        {
            throw ex;
        }

  }

    protected void ImportGridView_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
        ImportGridView.PageIndex = e.NewPageIndex;
        ImportGridView.DataBind();
    }


    protected void Import_Click(object sender, EventArgs e)
    {
        /**//////从EWS库取指标
        //StringBuilder indiCodes = new StringBuilder();
        //if (IndicatorMultiSelectControl1.SelectedIndicatorList != null)
        //{
        //    foreach (Indicator indi in IndicatorMultiSelectControl1.SelectedIndicatorList)
        //        indiCodes.Append("'" + indi.IndicatorCode + "',");//加逗号是因为参数里有逗号分隔符
        //}
        //if (indiCodes == null || indiCodes.Length == 0)
        //    return;

        //indiCodes.Remove(indiCodes.Length - 1, 1);//去掉加上的逗号


        /**////将其转化为XML文档                                   
        //SqlConnection PBCconn = new SqlConnection("server=localhost;Integrated Security=SSPI;database=PBCDataBaseTest;");

        //DataSet dsPBC = new DataSet();
        //SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM MonthBase where IndicatorID  in ( " + indiCodes.ToString() + " )", PBCconn);

        // MemoryStream memStrm = new MemoryStream();
        // StreamReader strmRead = new StreamReader(memStrm);
        // StreamWriter strmWrite = new StreamWriter(memStrm);
        List<Import_MonthBase> mbs = Session["PBCmonthbase"] as List<Import_MonthBase>;
        string file = "D:\\PBCmonth.xml";
        TextWriter writer = new StreamWriter(file);
        XmlSerializer sr = new XmlSerializer(typeof(List<Import_MonthBase>));
        sr.Serialize(writer, mbs);
        writer.Close();


         //da.Fill(dsPBC);
         //dsPBC.WriteXml(strmWrite, XmlWriteMode.IgnoreSchema);
         //memStrm.Seek(0, SeekOrigin.Begin);

         
         //dsPBC.WriteXml(file);

    }
}