当前路径：DAL/xml.cs     using System;
using System.Collections.Generic;
using System.Text;
using System.Configuration ;
using System.Collections;
using System.Xml;
using System.Xml.XPath;
using IDAL;
using Model;

namespace DAL
{
    class xml:Iguestbook 
    {
        string xmlGuestBookPath = System.Web.HttpContext.Current.Server.MapPath("../App_Data/") + ConfigurationSettings.AppSettings["xmlConnectionString"];   
        //得到所有留言
        public  guestbook[] getListGuestBook()
        {
            XmlDataDocument xmlDoc = new XmlDataDocument();
            xmlDoc.Load(xmlGuestBookPath);//打开留言本xml文档
            XmlNodeList xnl = xmlDoc.SelectSingleNode("guestBooks").ChildNodes;//读取所有结点
            XmlElement xe ;//声明一个元素
            ArrayList guest = new ArrayList();
            foreach (XmlNode xn in xnl)
            {
                guestbook gb = new guestbook();
                xe = (XmlElement)xn;//转换这个节点为一个元素
                gb.Time = DateTime.Parse(xe.GetAttribute("time"));//得到留言时间
                XmlNodeList xnlChild = xn.ChildNodes ;
                gb.Id = gb.Time.ToString();//以时间为主键
                gb.Name = xn.ChildNodes[0].InnerText;
                gb.Ip = xn.ChildNodes[1].InnerText;
                gb.Content = xn.ChildNodes[2].InnerText;
                gb.Recontent = xn.ChildNodes[3].InnerText;
                gb.Pic = xn.ChildNodes[4].InnerText;
                gb.Email = xn.ChildNodes[5].InnerText;
                guest.Add(gb);
            }
            guest.Reverse();//数组反转，最后一条留言在第一位显示
            return (guestbook[])guest.ToArray(typeof(guestbook));
        }
    

        //得到一条留言
        public  guestbook[] getOnly(string id)
        {
            
            guestbook  gb = new guestbook();
            ArrayList guest = new ArrayList();
            XmlDataDocument xmlDoc = new XmlDataDocument();
            xmlDoc.Load(xmlGuestBookPath);
            XmlNodeList xnl = xmlDoc.SelectSingleNode("guestBooks").ChildNodes;
            XmlElement xe;
            foreach (XmlNode xn in xnl)
            {
                xe = (XmlElement)xn;
                gb.Time  = DateTime.Parse (xe.GetAttribute("time"));
                gb.Id = gb.Time.ToString();//以时间为主键
                if (xe.GetAttribute("time") == id)
                {
                    XmlNodeList xnlChild = xn.ChildNodes;
                    gb.Name = xn.ChildNodes[0].InnerText;
                    gb.Ip = xn.ChildNodes[1].InnerText;
                    gb.Content = xn.ChildNodes[2].InnerText;
                    gb.Recontent = xn.ChildNodes[3].InnerText;
                    gb.Pic = xn.ChildNodes[4].InnerText;
                    gb.Email = xn.ChildNodes[5].InnerText;
                    guest.Add(gb);
                }
            }
            return (guestbook[])guest.ToArray(typeof(guestbook));
        }

        //添加留言内容
        public void setGuestBook(guestbook gb)
        {
            XmlDataDocument xmlDoc = new XmlDataDocument();
            xmlDoc.Load(this.xmlGuestBookPath);
            //选择根结点
            XmlNode root = xmlDoc.SelectSingleNode("guestBooks");
            XmlElement xe = xmlDoc.CreateElement("guestBook");//添加一个新结点元素
            xe.SetAttribute("time", gb.Time.ToString());//添加元素属性
            gb.Id = gb.Time.ToString();//以时间为关键字段

            XmlElement xesub1 = xmlDoc.CreateElement("name");//创建子无素name
            xesub1.InnerText = gb.Name;
            xe.AppendChild(xesub1);//添加到xe结点中

            XmlElement xesub2 = xmlDoc.CreateElement("ip");
            xesub2.InnerText = gb.Ip;
            xe.AppendChild(xesub2);

            XmlElement xesub3 = xmlDoc.CreateElement("content");
            xesub3.InnerText = gb.Content;
            xe.AppendChild(xesub3);

            XmlElement xesub4 = xmlDoc.CreateElement("recontent");
            xesub4.InnerText = gb.Recontent;
            xe.AppendChild(xesub4);

            XmlElement xesub5 = xmlDoc.CreateElement("pic");
            xesub5.InnerText = gb.Pic;
            xe.AppendChild(xesub5);

            XmlElement xesub6 = xmlDoc.CreateElement("email");
            xesub6.InnerText = gb.Email;
            xe.AppendChild(xesub6);

            root.AppendChild(xe);//新建节点添加到根结点中

            xmlDoc.Save(this.xmlGuestBookPath);//保存

        }

        //回复留言
        public void setReGuestBook(guestbook Regb)
        {
            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.Load(this.xmlGuestBookPath);
            XmlNodeList xnl = xmlDoc.SelectSingleNode("guestBooks").ChildNodes;
            foreach (XmlNode xn in xnl)
            {
                XmlElement xe = (XmlElement)xn;
                if (xe.GetAttribute("time") == Regb.Id)
                {
                    xe.ChildNodes[3].InnerText = Regb.Recontent;//添加回复内容
                }
            }
            xmlDoc.Save(this.xmlGuestBookPath);
        }

        //删除留言
        public bool delGuestBook(string time)
        {
            XmlDataDocument xmlDoc = new XmlDataDocument();
            xmlDoc.Load(this.xmlGuestBookPath);
            XmlNodeList  xnl = xmlDoc.SelectSingleNode("guestBooks").ChildNodes ;
            XmlNode xnroot = xmlDoc.SelectSingleNode("guestBooks");//查找根结点，为删除子结点做准备
            foreach (XmlNode xn in xnl)//循环所有子结点
            {
                XmlElement xe = (XmlElement)xn;
                if (xe.GetAttribute("time") == time) //对比是否是要删除的结点
                {
                    xnroot.RemoveChild(xe);//从根结点删除
                    xmlDoc.Save(this.xmlGuestBookPath);
                    return true;
                }
            }
            return false;
        }
    }
}