如何快速处理xml文件信息

这个范例是帮一个朋友做的，他写的处理代码速度是1笔/0.3秒，我重新写的代码运行数据1000笔/0.3秒。速度提升1000倍。代码如下。
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1、待处理的xml字符串数据
 
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<Positions from="51Job">
  <Company>
    <CorpName><![CDATA[北京XXXX有限公司]]></CorpName>
    <OfficeAddr1><![CDATA[北京市海淀区XXX大厦XXX座XXX层]]></OfficeAddr1>
    <OffPostCode1><![CDATA[100086]]></OffPostCode1>
    <CompanySize><![CDATA[XXX人以上]]></CompanySize>
    <TradeCodes>
      <TradeCode><![CDATA[办公用品及设备]]></TradeCode>
      <TradeCode><![CDATA[计算机硬件]]></TradeCode>
    </TradeCodes>
    <AboutUs><![CDATA[XXX数码办公企业创建于XXXX年XX月，历经XXXX年的发展，目前已成为以XXXX为中心的全国性股份制公司，旗下拥有XX家专业公司，分布于北京、上海、广州、武汉、成都、西安、长沙和南昌等核心城市，注册资金5000万元，在职员工近500名。  秉承“先进的技术、优质的产品、完善的服务、合理的价格”的经营理念，自公司创立以来，本公司的销售、技术服务、研发等高素质人才为各行各业的客户提供着从需求分析、产品咨询、专业培训、网络建设、软件开发、软件应用培训及维护、硬件销售、保养及维修、各种消耗品供应等一条龙的量身定做的专业化、规范化、人性化服务。  泰和数码办公企业重视培养人才，实行任人唯贤的人力资源政策，积极培养有理想、有道德、有责任感、有协作精神的现代化员工队伍，同时积极引进先进的管理理念，采用规范化、科学化的管理方法不断壮大自身实力。  公司始终坚持人才与企业共同发展的理念，关注员工的技能培训及发展，并不断加强企业文化的营建。公司业务的持续高速发展，也为员工担供了极大的发展空间。多元化的企业文化、以人为本的经营管理理念证明了泰和是一个良好的发展平台。     公司网站 http://www.XXXX.com.cn]]></AboutUs>
    <Websites>
      <Website><![CDATA[http://www.techhero.com.cn]]></Website>
    </Websites>
    <Informations>
      <Information>
        <Contact><![CDATA[人力资源部]]></Contact>
        <Addr><![CDATA[XXX市XXX区XX路XXX号XXX大厦A座10层]]></Addr>
        <OffPostCode><![CDATA[100086]]></OffPostCode>
      </Information>
    </Informations>
  </Company>
  <Position>
    <ReleaseDate><![CDATA[2011-04-14]]></ReleaseDate>
    <Description><![CDATA[岗位职责：１，主要负责杭州市内复印机等办公设备的日常保养和故障处理，维系客情关系；２，在为所负责区域的客户做保养或维修的同时进行硒鼓、纸张等办公耗材的销售工作。岗位要求：１，中专以上学历，计算机或电子类相关专业；２，熟悉杭州地形，能吃苦，有上进心；３，喜欢动手，有相关工作经验者优先。薪资福利：底薪＋提成＋工作餐＋五险一金＋高温补贴＋带薪培训＋免费体检＋节日费等]]></Description>
    <PositionName><![CDATA[复印机维修工程师]]></PositionName>
    <Number><![CDATA[5]]></Number>
    <Education><![CDATA[中专]]></Education>
    <Salary><![CDATA[2000-2999]]></Salary>
    <Citys>
      <City><![CDATA[杭州]]></City>
    </Citys>
    <Emails>
      <Email><![CDATA[zhouqiaoyan@techhero.com.cn]]></Email>
    </Emails>
    <URLFrom>http://search.51job.com/job/45205821,c.html</URLFrom>
    <SnapshoAddr>{117BD768-CA9A-4D75-9C47-BB30E638FCE2}.html</SnapshoAddr>
  </Position>
</Positions>
 
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2、test01.aspx.cs代码如下
 
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using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq; 
using System.Collections.Generic;
using System.Xml;
 
 
 
 
namespace Test.xml
{
    public partial class test01 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                DateTime begin = System.DateTime.Now;
                TimeSpan span = begin - begin;
                Positions obj = new Positions();
                int num = 10000;
                for (int i = 0; i < num; i++)
                {
                    this.MakeData(Server.MapPath("~/Xml/work.xml"), ref obj);
                    obj.Dispose();
                }
                DateTime end = DateTime.Now;
                span = end - begin;
                this.Page.Response.Write(string.Format("span = {0}<br/> begin = {1}<br/> end = {2}<br/>"
                    , span.ToString()
                    , begin.ToString("yyyy/MM/dd HH:mm:ss:fff")
                    , end.ToString("yyyy/MM/dd HH:mm:ss:fff")
                    )); 
            }
        }
 
        /// <summary>
        /// 处理xml数据主函数
        /// 1、可以处理xml文件，见xdoc.Load(string xmlPath)
        /// 2、可以处理xml字符串，见xdoc.Load(string xmlInfo)
        /// 自己根据需要，调整函数参数和注释代码
        /// </summary>
        private void MakeData(string fpath,ref Positions obj)
        {
            string fpah = Server.MapPath("~/Xml/work.xml");
            // xdoc.LoadXml(strXml);
            System.Xml.XmlDocument xdoc = null; 
            try
            {
                xdoc = new System.Xml.XmlDocument();
                xdoc.Load(fpah);
                if (xdoc.ChildNodes.Count > 0)
                {
                    obj = new Positions();
                    foreach (XmlNode node in xdoc.ChildNodes[0].ChildNodes)
                    {
                        this.MakePoints(node, obj);
                    }
                }
            }
            catch (Exception ex)
            {
                //
            }
            finally
            { 
                xdoc = null;
            }
        }
 
        /// <summary>
        /// 根据xml借点，处理该节点的子节点和属性，并将数据保存到自定义对象中
        /// </summary>
        /// <param name="node"></param>
        /// <param name="obj"></param>
        private void MakePoints(XmlNode node, Positions obj)
        {
            string name = node.Name.Trim();
            switch (name)
            {
                case "Company":
                    {
                        this.Fun_Company(node, obj);
                        break;
                    }
                case "Position":
                    {
                        this.Fun_Position(node, obj);
                        break;
                    }
 
            }
        }
 
        /// <summary>
        /// Company大节点解析处理数据，并且保存数据到自定义对象Company
        /// </summary>
        /// <param name="node"></param>
        /// <param name="obj"></param>
        protected void Fun_Company(XmlNode node, Positions obj)
        {
            obj.MyCompany = new Company
            {
                CorpName = node.SelectSingleNode("descendant::CorpName").InnerText,
                OfficeAddr1 = this.Fun_Single(node, "OfficeAddr1", obj),
                OffPostCode1 = this.Fun_Single(node, "OffPostCode1", obj),
                CompanySize = this.Fun_Single(node, "CompanySize", obj),
                AboutUs = this.Fun_Single(node, "AboutUs", obj),
            };
            this.Fun_Multi(node.SelectSingleNode("descendant::TradeCodes"), obj);
            this.Fun_Multi(node.SelectSingleNode("descendant::Websites"), obj);
            this.Fun_Multi(node.SelectSingleNode("descendant::Informations"), obj);
        }
 
        /// <summary>
        /// Position大节点解析处理数据，并且保存数据到自定义对象Position
        /// </summary>
        /// <param name="node"></param>
        /// <param name="obj"></param>
        private void Fun_Position(XmlNode node, Positions obj)
        {
            obj.MyPosition = new Position
            {
                ReleaseDate = this.Fun_Single(node, "ReleaseDate", obj),
                Description = this.Fun_Single(node, "Description", obj),
                PositionName = this.Fun_Single(node, "PositionName", obj),
                Number = this.Fun_Single(node, "Number", obj),
                Education = this.Fun_Single(node, "Education", obj),
                Salary = this.Fun_Single(node, "Salary", obj),
                URLFrom = this.Fun_Single(node, "URLFrom", obj),
                SnapshoAddr = this.Fun_Single(node, "SnapshoAddr", obj),
            };
            this.Fun_Multi(node.SelectSingleNode("descendant::Citys"), obj);
            this.Fun_Multi(node.SelectSingleNode("descendant::Emails"), obj);
        }
 
        /// <summary>
        /// 处理没有子节点的xml节点，并且保留所有数据到自定义对象
        /// </summary>
        /// <param name="node"></param>
        /// <param name="child"></param>
        /// <param name="obj"></param>
        /// <returns></returns>
        private string Fun_Single(XmlNode node, string child, Positions obj)
        {
            string resutl = "";
            resutl = node.SelectSingleNode(string.Format("descendant::{0}", child)).InnerText;
            return resutl;
        }
 
        /// <summary>
        /// 处理有若干子节点的xml节点，并且保留所有数据到自定义对象
        /// </summary>
        /// <param name="node"></param>
        /// <param name="obj"></param>
        private void Fun_Multi(XmlNode node, Positions obj)
        {
            switch (node.Name)
            {
                case "TradeCodes":
                    {
                        foreach (XmlNode i in node.ChildNodes)
                        {
                            obj.MyCompany.TradeCodes.Add(i.InnerText);
                        }
                        break;
                    }
 
                case "Informations":
                    {
                        foreach (XmlNode i in node.ChildNodes)
                        {
                            Dictionary<string, string> item = new Dictionary<string, string>();
                            obj.MyCompany.Informations.Add(item);
                            foreach (XmlNode j in i.ChildNodes)
                            {
                                item.Add(j.Name, j.InnerText);
                            }
                        }
                        break;
                    }
 
                case "Websites":
                    {
                        foreach (XmlNode i in node.ChildNodes)
                        {
                            obj.MyCompany.Websites.Add(i.InnerText);
                        }
                        break;
                    }
 
 
                case "Citys":
                    {
                        foreach (XmlNode i in node.ChildNodes)
                        {
                            obj.MyPosition.Citys.Add(i.InnerText);
                        }
                        break;
                    }
 
                case "Emails":
                    {
                        foreach (XmlNode i in node.ChildNodes)
                        {
                            obj.MyPosition.Emails.Add(i.InnerText);
                        }
                        break;
                    }
            }
        }
    }
 
    /// <summary>
    /// 根据Xml属性定义的类
    /// </summary>
    public class Positions : BaseClass
    {
        public Positions()
        {
            this.MyCompany = new Company();
            this.MyPosition = new Position();
        }
 
        public Company MyCompany
        {
            get;
            set;
        }
 
        public Position MyPosition
        {
            get;
            set;
        }
    }
 
    public class Company : BaseClass
    {
        public Company()
        {
            this.TradeCodes = new List<string>();
            this.Websites = new List<string>();
            this.Informations = new List<Dictionary<string, string>>();
        }
 
        public string CorpName
        {
            get;
            set;
        }
 
        public string OfficeAddr1
        {
            get;
            set;
        }
 
        public string OffPostCode1
        {
            get;
            set;
        }
 
        public string CompanySize
        {
            get;
            set;
        }
 
        public List<string> TradeCodes
        {
            get;
            set;
        }
 
        public string AboutUs
        {
            get;
            set;
        }
 
        public List<string> Websites
        {
            get;
            set;
        }
 
        public List<Dictionary<string, string>> Informations
        {
            get;
            set;
        }
    }
 
    public class Position : BaseClass
    {
        public Position()
        {
            this.Citys = new List<string>();
            this.Emails = new List<string>();
        }
 
        public string ReleaseDate
        {
            get;
            set;
        }
 
        public string Description
        {
            get;
            set;
        }
 
        public string PositionName
        {
            get;
            set;
        }
 
        public string Number
        {
            get;
            set;
        }
 
        public string Education
        {
            get;
            set;
        }
 
        public string Salary
        {
            get;
            set;
        }
 
        public List<string> Citys
        {
            get;
            set;
        }
 
        public List<string> Emails
        {
            get;
            set;
        }
 
        public string URLFrom
        {
            get;
            set;
        }
 
        public string SnapshoAddr
        {
            get;
            set;
        }
    }
 
    public class BaseClass:IDisposable
    {
        public void Dispose()
        {
        }
    }
}