.net 收邮件

/*
 * CopyRight @ taopu软件工作室  
 * 软件构架师: 陶晓铮 
 * 代码实现: puha
 * 
 * 功能: 收邮件 
 * 文件名: Pop3Server.cs
 * 
*/
using System;
using System.Collections.Generic;
using System.Text;
using System.Net.Sockets;
using System.IO;
using System.Collections;

namespace ConsoleApplication1
{
    public class Pop3Server
    {
        #region 常量区
        private const string COMMAND_DELE = "dele ";
        private const string COMMAND_RETR = "retr ";
        private const string COMMAND_SEP = " ";
        private const string VALUE_USER = "user ";
        private const string VALUE_PASS = "pass ";
        private const string VALUE_ERR = "-ERR";
        private const int DEFUALT_PORT = 110;
        private const string DEFUALT_HOST = "localhost";
        #endregion

        #region 变量区
        private string _sHost;
        private string _sPassWord;
        private string _sUserName;
        private int _iPort;
        private string _sErrorMsg = "";
        private TcpClient _tcpClient;
        private NetworkStream ns;
        #endregion

        #region 属性区
        /// <summary>
        /// 邮件服务器名称 defual laocalhost
        /// </summary>
        public string Host
        {
            set
            {
                _sHost = value;
            }
        }
        /// <summary>
        /// 用户密码
        /// </summary>
        public string PassWord
        {
            set
            {
                _sPassWord = value;
            }
        }
        /// <summary>
        /// 用户名
        /// </summary>
        public string UserName
        {
            set
            {
                _sUserName = value;
            }
        }
        /// <summary>
        /// 端口,defualt 110
        /// </summary>
        public int Port
        {
            set
            {
                _iPort = value;
            }
        }
        /// <summary>
        /// 错误信息
        /// </summary>
        public string ErrorMsg
        {
            get
            {
                return _sErrorMsg;
            }
        }
        #endregion

        #region 构造器
        /// <summary>
        /// 构造器，要求服务器和端口
        /// </summary>
        /// <param name="sUserName">用户名</param>
        /// <param name="sPassWord">密码</param>
        /// <param name="sHost">服务器名称</param>
        /// <param name="iPort">端口号</param>
        public Pop3Server(string sUserName, string sPassWord, string sHost, int iPort)
        {
            _sUserName = sUserName;
            _sPassWord = sPassWord;
            _sHost = sHost;
            _iPort = iPort;
        }
        /// <summary>
        /// 构造器,使用默认端口号、服务器
        /// </summary>
        /// <param name="sUserName"></param>
        /// <param name="sPassWord"></param>
        public Pop3Server(string sUserName, string sPassWord)
            : this(sUserName, sPassWord, DEFUALT_HOST, DEFUALT_PORT)
        {
            //
        }
        #endregion

        #region 可访问方法
        /// <summary>
        /// 连结到服务器,成功返回真
        /// </summary>
        /// <returns>成功返回真</returns>
        public Boolean DoConnect()
        {
            try
            {
                _tcpClient = new TcpClient(_sHost, _iPort);
                byte[] outbytes;
                string input;


                ns = _tcpClient.GetStream();
                StreamReader sr = new StreamReader(ns);

                sr.ReadLine();
                input = VALUE_USER + _sUserName + COMMAND_SEP;
                outbytes = System.Text.Encoding.ASCII.GetBytes(input.ToCharArray());
                ns.Write(outbytes, 0, outbytes.Length);
                sr.ReadLine();

                input = VALUE_PASS + _sPassWord + COMMAND_SEP;
                outbytes = System.Text.Encoding.ASCII.GetBytes(input.ToCharArray());
                ns.Write(outbytes, 0, outbytes.Length);
                sr.ReadLine();
                return true;
            }
            catch (SocketException ex)
            {
                _sErrorMsg = ex.SocketErrorCode.ToString();
                return false;
            }
            //
        }
        /// <summary>
        /// 删除邮件,成功返回真
        /// </summary>
        /// <param name="iIndex">邮件序号</param>
        /// <returns>成功返回真</returns>
        public Boolean DoDeleteMail(int iIndex)
        {
            Byte[] outbytes;
            string input;
            try
            {
                input = COMMAND_DELE + iIndex.ToString() + COMMAND_SEP;
                outbytes = Encoding.ASCII.GetBytes(input.ToCharArray());
                ns.Write(outbytes, 0, outbytes.Length);
            }
            catch (SocketException ex)
            {
                _sErrorMsg = ex.SocketErrorCode.ToString();
                return false;
            }
            return true;

        }
        /// <summary>
        /// 按序号取回邮件, 错误时返回null
        /// </summary>
        /// <param name="iIndex">邮件序号</param>
        /// <returns>返回邮件对象 RecMailMsg, 错误时返回null</returns>
        public RecMailMsg GetMail(int iIndex)
        {
            //如果没有连结,连结到服务器
            if ((_tcpClient == null) || (!_tcpClient.Connected))
            {
                if (!DoConnect())
                {
                    return null;
                }
            }

            //取回邮件内容,置入 ArrayList
            ArrayList msglines = GetSubMail(iIndex);
            if (msglines == null)
            {
                return null;
            }

            //测试,保存到本地,查看内容
            saveToFile(msglines);

            //分解邮件各部份
            MailDecode mailDec = new MailDecode(msglines);
            RecMailMsg mail = new RecMailMsg();

            //取回邮件详细信息
            mail.Subj = GetMailSubject(mailDec.mailHeard);
            mail.From = GetMailFrom(mailDec.mailHeard);
            mail.Date = GetMailDate(mailDec.mailHeard);

            //返回邮件对象
            return mail;
        }
        #endregion

        #region 内部方法
        /// <summary>
        /// 测试, 保存邮件内容到本地
        /// </summary>
        /// <param name="msglines"></param>
        private void saveToFile(ArrayList msglines)
        {
            //合法邮件名测试
            string sFileName = "c:/mail";
            while (File.Exists(sFileName + ".txt"))
            {
                sFileName = sFileName + "i";
            }

            //保存
            sFileName = sFileName + ".txt";
            using (StreamWriter sw = File.CreateText(sFileName))
            {
                IEnumerator msgenum = msglines.GetEnumerator();
                string line = "";
                while (msgenum.MoveNext())
                {
                    line = (string)msgenum.Current;
                    sw.WriteLine(line);
                }
                sw.Close();

            }
        }
        /// <summary>
        /// 返回指定序号邮件内容,错误返回null
        /// </summary>
        /// <param name="iIndex">邮件序号</param>
        /// <returns>邮件内容,以ArrayList返回, 错误返回null</returns>
        private ArrayList GetSubMail(int iIndex)
        {
            //准备
            Byte[] outbytes;
            string input;
            string line = "";

            //在异常保护中送入命令
            input = COMMAND_RETR + iIndex.ToString() + COMMAND_SEP;
            outbytes = Encoding.ASCII.GetBytes(input.ToCharArray());
            StreamReader sr;
            try
            {
                ns.Write(outbytes, 0, outbytes.Length);
                sr = new StreamReader(ns);
                line = sr.ReadLine();
                if (line.StartsWith(VALUE_ERR))
                {
                    _sErrorMsg = line;
                    return null;
                }
            }
            catch (SocketException ex)
            {
                _sErrorMsg = ex.SocketErrorCode.ToString();
                return null;
            }

            //置入arrayList
            ArrayList msglines = new ArrayList();
            do
            {
                line = sr.ReadLine();
                msglines.Add(line);
            } while (line != ".");
            msglines.RemoveAt(msglines.Count - 1);

            return msglines;
        }
        /// <summary>
        /// 得到邮件内容
        /// </summary>
        /// <param name="msglines">邮件头Array</param>
        /// <returns>得到邮件内容</returns>
        private string GetMailSubject(ArrayList msglines)
        {
            string[] tokens;
            IEnumerator msgenum = msglines.GetEnumerator();
            while (msgenum.MoveNext())
            {
                string line = (string)msgenum.Current;

                if (line.StartsWith("subject:"))
                {
                    tokens = line.Split(new Char[] { ' ' });
                    return tokens[1].Trim();
                }
            }
            return "None";
        }
        /// <summary>
        /// 得到发件人
        /// </summary>
        /// <param name="msglines"></param>
        /// <returns>发件人地址</returns>
        private string GetMailFrom(ArrayList msglines)
        {
            string[] tokens;
            IEnumerator msgenum = msglines.GetEnumerator();
            while (msgenum.MoveNext())
            {
                string line = (string)msgenum.Current;
                if (line.StartsWith("from:"))
                {
                    tokens = line.Split(':');
                    return tokens[1].Trim();
                }
            }
            return "None";
        }
        /// <summary>
        /// 得到发件日期
        /// </summary>
        /// <param name="msglines"></param>
        /// <returns>发件日期</returns>
        private string GetMailDate(ArrayList msglines)
        {
            string[] tokens;
            IEnumerator msgenum = msglines.GetEnumerator();
            while (msgenum.MoveNext())
            {
                string line = (string)msgenum.Current;
                if (line.StartsWith("date:"))
                {
                    tokens = line.Split(':');
                    return tokens[1].Trim();

                }
            }
            return "None";
        }
        #endregion
    }
       
}