FTPClientHelper辅助类 实现文件上传，目录操作，下载等操作

string userName = "xxx";
string password = "xxx";
var ftp = new FTPClientHelper("xxx", ".", userName, password, 1021);

//-------------------------------------------------------------------------------------
// All Rights Reserved , Copyright (C) 2015 , ZTO , Ltd .
//-------------------------------------------------------------------------------------

using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;

namespace ZTO.PicTest.Utilities
{
  /// <summary>
  /// FTP操作帮助类
  ///
  /// 修改纪录
  ///
  ///     2016-4-4 版本：1.0 YangHengLian 创建主键，注意命名空间的排序，测试非常好。
  /// 
  /// 版本：1.0
  ///
  /// <author>
  ///    <name>YangHengLian</name>
  ///    <date>2016-4-4</date>
  /// </author>
  /// </summary>
  public class FTPClientHelper
  {
    public static object Obj = new object();

    #region 构造函数
    /// <summary>
    /// 缺省构造函数
    /// </summary>
    public FTPClientHelper()
    {
      RemoteHost = "";
      _strRemotePath = "";
      _strRemoteUser = "";
      _strRemotePass = "";
      _strRemotePort = 21;
      _bConnected = false;
    }

    /// <summary>
    /// 构造函数
    /// </summary>
    public FTPClientHelper(string remoteHost, string remotePath, string remoteUser, string remotePass, int remotePort)
    {
      // Ip地址
      RemoteHost = remoteHost;
      // 这个很重要，表示连接路径，如果是.表示根目录
      _strRemotePath = remotePath;
      // 登录账号
      _strRemoteUser = remoteUser;
      // 登录密码
      _strRemotePass = remotePass;
      // ftp端口号
      _strRemotePort = remotePort;

      Connect();
    }
    #endregion

    #region 字段
    private int _strRemotePort;
    private Boolean _bConnected;
    private string _strRemotePass;
    private string _strRemoteUser;
    private string _strRemotePath;

    /// <summary>
    /// 服务器返回的应答信息(包含应答码)
    /// </summary>
    private string _strMsg;
    /// <summary>
    /// 服务器返回的应答信息(包含应答码)
    /// </summary>
    private string _strReply;
    /// <summary>
    /// 服务器返回的应答码
    /// </summary>
    private int _iReplyCode;
    /// <summary>
    /// 进行控制连接的socket
    /// </summary>
    private Socket _socketControl;
    /// <summary>
    /// 传输模式
    /// </summary>
    private TransferType _trType;

    /// <summary>
    /// 接收和发送数据的缓冲区
    /// </summary>
    private const int BlockSize = 512;

    /// <summary>
    /// 编码方式
    /// </summary>
    readonly Encoding _ascii = Encoding.ASCII;
    /// <summary>
    /// 字节数组
    /// </summary>
    readonly Byte[] _buffer = new Byte[BlockSize];
    #endregion

    #region 属性

    /// <summary>
    /// FTP服务器IP地址
    /// </summary>
    public string RemoteHost { get; set; }

    /// <summary>
    /// FTP服务器端口
    /// </summary>
    public int RemotePort
    {
      get
      {
        return _strRemotePort;
      }
      set
      {
        _strRemotePort = value;
      }
    }

    /// <summary>
    /// 当前服务器目录
    /// </summary>
    public string RemotePath
    {
      get
      {
        return _strRemotePath;
      }
      set
      {
        _strRemotePath = value;
      }
    }

    /// <summary>
    /// 登录用户账号
    /// </summary>
    public string RemoteUser
    {
      set
      {
        _strRemoteUser = value;
      }
    }

    /// <summary>
    /// 用户登录密码
    /// </summary>
    public string RemotePass
    {
      set
      {
        _strRemotePass = value;
      }
    }

    /// <summary>
    /// 是否登录
    /// </summary>
    public bool Connected
    {
      get
      {
        return _bConnected;
      }
    }
    #endregion

    #region 链接
    /// <summary>
    /// 建立连接 
    /// </summary>
    public void Connect()
    {
      lock (Obj)
      {
        _socketControl = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
        var ep = new IPEndPoint(IPAddress.Parse(RemoteHost), _strRemotePort);
        try
        {
          _socketControl.Connect(ep);
        }
        catch (Exception)
        {
          throw new IOException("不能连接ftp服务器");
        }
      }
      ReadReply();
      if (_iReplyCode != 220)
      {
        DisConnect();
        throw new IOException(_strReply.Substring(4));
      }
      SendCommand("USER " + _strRemoteUser);
      if (!(_iReplyCode == 331 || _iReplyCode == 230))
      {
        CloseSocketConnect();
        throw new IOException(_strReply.Substring(4));
      }
      if (_iReplyCode != 230)
      {
        SendCommand("PASS " + _strRemotePass);
        if (!(_iReplyCode == 230 || _iReplyCode == 202))
        {
          CloseSocketConnect();
          throw new IOException(_strReply.Substring(4));
        }
      }
      _bConnected = true;
      ChDir(_strRemotePath);
    }

    /// <summary>
    /// 关闭连接
    /// </summary>
    public void DisConnect()
    {
      if (_socketControl != null)
      {
        SendCommand("QUIT");
      }
      CloseSocketConnect();
    }
    #endregion

    #region 传输模式
    /// <summary>
    /// 传输模式:二进制类型、ASCII类型
    /// </summary>
    public enum TransferType { Binary, ASCII };

    /// <summary>
    /// 设置传输模式
    /// </summary>
    /// <param name="ttType">传输模式</param>
    public void SetTransferType(TransferType ttType)
    {
      SendCommand(ttType == TransferType.Binary ? "TYPE I" : "TYPE A");
      if (_iReplyCode != 200)
      {
        throw new IOException(_strReply.Substring(4));
      }
      _trType = ttType;
    }

    /// <summary>
    /// 获得传输模式
    /// </summary>
    /// <returns>传输模式</returns>
    public TransferType GetTransferType()
    {
      return _trType;
    }
    #endregion

    #region 文件操作
    /// <summary>
    /// 获得文件列表
    /// </summary>
    /// <param name="strMask">文件名的匹配字符串</param>
    public string[] Dir(string strMask)
    {
      if (!_bConnected)
      {
        Connect();
      }
      Socket socketData = CreateDataSocket();
      SendCommand("NLST " + strMask);
      if (!(_iReplyCode == 150 || _iReplyCode == 125 || _iReplyCode == 226))
      {
        throw new IOException(_strReply.Substring(4));
      }
      _strMsg = "";
      Thread.Sleep(2000);
      while (true)
      {
        int iBytes = socketData.Receive(_buffer, _buffer.Length, 0);
        _strMsg += _ascii.GetString(_buffer, 0, iBytes);
        if (iBytes < _buffer.Length)
        {
          break;
        }
      }
      char[] seperator = { '\n' };
      string[] strsFileList = _strMsg.Split(seperator);
      socketData.Close(); //数据socket关闭时也会有返回码
      if (_iReplyCode != 226)
      {
        ReadReply();
        if (_iReplyCode != 226)
        {

          throw new IOException(_strReply.Substring(4));
        }
      }
      return strsFileList;
    }

    public void NewPutByGuid(string strFileName, string strGuid)
    {
      if (!_bConnected)
      {
        Connect();
      }
      string str = strFileName.Substring(0, strFileName.LastIndexOf("\\", StringComparison.Ordinal));
      string strTypeName = strFileName.Substring(strFileName.LastIndexOf(".", StringComparison.Ordinal));
      strGuid = str + "\\" + strGuid;
      Socket socketData = CreateDataSocket();
      SendCommand("STOR " + Path.GetFileName(strGuid));
      if (!(_iReplyCode == 125 || _iReplyCode == 150))
      {
        throw new IOException(_strReply.Substring(4));
      }
      var input = new FileStream(strGuid, FileMode.Open);
      input.Flush();
      int iBytes;
      while ((iBytes = input.Read(_buffer, 0, _buffer.Length)) > 0)
      {
        socketData.Send(_buffer, iBytes, 0);
      }
      input.Close();
      if (socketData.Connected)
      {
        socketData.Close();
      }
      if (!(_iReplyCode == 226 || _iReplyCode == 250))
      {
        ReadReply();
        if (!(_iReplyCode == 226 || _iReplyCode == 250))
        {
          throw new IOException(_strReply.Substring(4));
        }
      }
    }

    /// <summary>
    /// 获取文件大小
    /// </summary>
    /// <param name="strFileName">文件名</param>
    /// <returns>文件大小</returns>
    public long GetFileSize(string strFileName)
    {
      if (!_bConnected)
      {
        Connect();
      }
      SendCommand("SIZE " + Path.GetFileName(strFileName));
      long lSize;
      if (_iReplyCode == 213)
      {
        lSize = Int64.Parse(_strReply.Substring(4));
      }
      else
      {
        throw new IOException(_strReply.Substring(4));
      }
      return lSize;
    }

    /// <summary>
    /// 获取文件信息
    /// </summary>
    /// <param name="strFileName">文件名</param>
    /// <returns>文件大小</returns>
    public string GetFileInfo(string strFileName)
    {
      if (!_bConnected)
      {
        Connect();
      }
      Socket socketData = CreateDataSocket();
      SendCommand("LIST " + strFileName);
      if (!(_iReplyCode == 150 || _iReplyCode == 125
        || _iReplyCode == 226 || _iReplyCode == 250))
      {
        throw new IOException(_strReply.Substring(4));
      }
      byte[] b = new byte[512];
      MemoryStream ms = new MemoryStream();

      while (true)
      {
        int iBytes = socketData.Receive(b, b.Length, 0);
        ms.Write(b, 0, iBytes);
        if (iBytes <= 0)
        {

          break;
        }
      }
      byte[] bt = ms.GetBuffer();
      string strResult = Encoding.ASCII.GetString(bt);
      ms.Close();
      return strResult;
    }

    /// <summary>
    /// 删除
    /// </summary>
    /// <param name="strFileName">待删除文件名</param>
    public void Delete(string strFileName)
    {
      if (!_bConnected)
      {
        Connect();
      }
      SendCommand("DELE " + strFileName);
      if (_iReplyCode != 250)
      {
        throw new IOException(_strReply.Substring(4));
      }
    }

    /// <summary>
    /// 重命名(如果新文件名与已有文件重名,将覆盖已有文件)
    /// </summary>
    /// <param name="strOldFileName">旧文件名</param>
    /// <param name="strNewFileName">新文件名</param>
    public void Rename(string strOldFileName, string strNewFileName)
    {
      if (!_bConnected)
      {
        Connect();
      }
      SendCommand("RNFR " + strOldFileName);
      if (_iReplyCode != 350)
      {
        throw new IOException(_strReply.Substring(4));
      }
      // 如果新文件名与原有文件重名,将覆盖原有文件
      SendCommand("RNTO " + strNewFileName);
      if (_iReplyCode != 250)
      {
        throw new IOException(_strReply.Substring(4));
      }
    }
    #endregion

    #region 上传和下载
    /// <summary>
    /// 下载一批文件
    /// </summary>
    /// <param name="strFileNameMask">文件名的匹配字符串</param>
    /// <param name="strFolder">本地目录(不得以\结束)</param>
    public void Get(string strFileNameMask, string strFolder)
    {
      if (!_bConnected)
      {
        Connect();
      }
      string[] strFiles = Dir(strFileNameMask);
      foreach (string strFile in strFiles)
      {
        if (!strFile.Equals(""))//一般来说strFiles的最后一个元素可能是空字符串
        {
          Get(strFile, strFolder, strFile);
        }
      }
    }

    /// <summary>
    /// 下载一个文件
    /// </summary>
    /// <param name="strRemoteFileName">要下载的文件名</param>
    /// <param name="strFolder">本地目录(不得以\结束)</param>
    /// <param name="strLocalFileName">保存在本地时的文件名</param>
    public void Get(string strRemoteFileName, string strFolder, string strLocalFileName)
    {
      Socket socketData = CreateDataSocket();
      try
      {
        if (!_bConnected)
        {
          Connect();
        }
        SetTransferType(TransferType.Binary);
        if (strLocalFileName.Equals(""))
        {
          strLocalFileName = strRemoteFileName;
        }
        SendCommand("RETR " + strRemoteFileName);
        if (!(_iReplyCode == 150 || _iReplyCode == 125 || _iReplyCode == 226 || _iReplyCode == 250))
        {
          throw new IOException(_strReply.Substring(4));
        }
        var output = new FileStream(strFolder + "\\" + strLocalFileName, FileMode.Create);
        while (true)
        {
          int iBytes = socketData.Receive(_buffer, _buffer.Length, 0);
          output.Write(_buffer, 0, iBytes);
          if (iBytes <= 0)
          {
            break;
          }
        }
        output.Close();
        if (socketData.Connected)
        {
          socketData.Close();
        }
        if (!(_iReplyCode == 226 || _iReplyCode == 250))
        {
          ReadReply();
          if (!(_iReplyCode == 226 || _iReplyCode == 250))
          {
            throw new IOException(_strReply.Substring(4));
          }
        }
      }
      catch
      {
        socketData.Close();
        _socketControl.Close();
        _bConnected = false;
        _socketControl = null;
      }
    }

    /// <summary>
    /// 下载一个文件
    /// </summary>
    /// <param name="strRemoteFileName">要下载的文件名</param>
    /// <param name="strFolder">本地目录(不得以\结束)</param>
    /// <param name="strLocalFileName">保存在本地时的文件名</param>
    public void GetNoBinary(string strRemoteFileName, string strFolder, string strLocalFileName)
    {
      if (!_bConnected)
      {
        Connect();
      }

      if (strLocalFileName.Equals(""))
      {
        strLocalFileName = strRemoteFileName;
      }
      Socket socketData = CreateDataSocket();
      SendCommand("RETR " + strRemoteFileName);
      if (!(_iReplyCode == 150 || _iReplyCode == 125 || _iReplyCode == 226 || _iReplyCode == 250))
      {
        throw new IOException(_strReply.Substring(4));
      }
      var output = new FileStream(strFolder + "\\" + strLocalFileName, FileMode.Create);
      while (true)
      {
        int iBytes = socketData.Receive(_buffer, _buffer.Length, 0);
        output.Write(_buffer, 0, iBytes);
        if (iBytes <= 0)
        {
          break;
        }
      }
      output.Close();
      if (socketData.Connected)
      {
        socketData.Close();
      }
      if (!(_iReplyCode == 226 || _iReplyCode == 250))
      {
        ReadReply();
        if (!(_iReplyCode == 226 || _iReplyCode == 250))
        {
          throw new IOException(_strReply.Substring(4));
        }
      }
    }

    /// <summary>
    /// 上传一批文件
    /// </summary>
    /// <param name="strFolder">本地目录(不得以\结束)</param>
    /// <param name="strFileNameMask">文件名匹配字符(可以包含*和?)</param>
    public void Put(string strFolder, string strFileNameMask)
    {
      string[] strFiles = Directory.GetFiles(strFolder, strFileNameMask);
      foreach (string strFile in strFiles)
      {
        Put(strFile);
      }
    }

    /// <summary>
    /// 上传一个文件
    /// </summary>
    /// <param name="strFileName">本地文件名</param>
    public void Put(string strFileName)
    {
      if (!_bConnected)
      {
        Connect();
      }
      Socket socketData = CreateDataSocket();
      if (Path.GetExtension(strFileName) == "")
        SendCommand("STOR " + Path.GetFileNameWithoutExtension(strFileName));
      else
        SendCommand("STOR " + Path.GetFileName(strFileName));

      if (!(_iReplyCode == 125 || _iReplyCode == 150))
      {
        throw new IOException(_strReply.Substring(4));
      }

      var input = new FileStream(strFileName, FileMode.Open);
      int iBytes;
      while ((iBytes = input.Read(_buffer, 0, _buffer.Length)) > 0)
      {
        socketData.Send(_buffer, iBytes, 0);
      }
      input.Close();
      if (socketData.Connected)
      {
        socketData.Close();
      }
      if (!(_iReplyCode == 226 || _iReplyCode == 250))
      {
        ReadReply();
        if (!(_iReplyCode == 226 || _iReplyCode == 250))
        {
          throw new IOException(_strReply.Substring(4));
        }
      }
    }

    /// <summary>
    /// 上传一个文件
    /// </summary>
    /// <param name="strFileName">本地文件名</param>
    /// 
    /// <param name="strGuid"> </param>
    public void PutByGuid(string strFileName, string strGuid)
    {
      if (!_bConnected)
      {
        Connect();
      }
      string str = strFileName.Substring(0, strFileName.LastIndexOf("\\", StringComparison.Ordinal));
      string strTypeName = strFileName.Substring(strFileName.LastIndexOf(".", System.StringComparison.Ordinal));
      strGuid = str + "\\" + strGuid;
      File.Copy(strFileName, strGuid);
      File.SetAttributes(strGuid, FileAttributes.Normal);
      Socket socketData = CreateDataSocket();
      SendCommand("STOR " + Path.GetFileName(strGuid));
      if (!(_iReplyCode == 125 || _iReplyCode == 150))
      {
        throw new IOException(_strReply.Substring(4));
      }
      var input = new FileStream(strGuid, FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.Read);
      int iBytes = 0;
      while ((iBytes = input.Read(_buffer, 0, _buffer.Length)) > 0)
      {
        socketData.Send(_buffer, iBytes, 0);
      }
      input.Close();
      File.Delete(strGuid);
      if (socketData.Connected)
      {
        socketData.Close();
      }
      if (!(_iReplyCode == 226 || _iReplyCode == 250))
      {
        ReadReply();
        if (!(_iReplyCode == 226 || _iReplyCode == 250))
        {
          throw new IOException(_strReply.Substring(4));
        }
      }
    }
    #endregion

    #region 目录操作
    /// <summary>
    /// 创建目录
    /// </summary>
    /// <param name="strDirName">目录名</param>
    public void MkDir(string strDirName)
    {
      if (!_bConnected)
      {
        Connect();
      }
      SendCommand("MKD " + strDirName);
      if (_iReplyCode != 257)
      {
        throw new IOException(_strReply.Substring(4));
      }
    }

    /// <summary>
    /// 删除目录
    /// </summary>
    /// <param name="strDirName">目录名</param>
    public void RmDir(string strDirName)
    {
      if (!_bConnected)
      {
        Connect();
      }
      SendCommand("RMD " + strDirName);
      if (_iReplyCode != 250)
      {
        throw new IOException(_strReply.Substring(4));
      }
    }

    /// <summary>
    /// 改变目录
    /// </summary>
    /// <param name="strDirName">新的工作目录名</param>
    public void ChDir(string strDirName)
    {
      if (strDirName.Equals(".") || strDirName.Equals(""))
      {
        return;
      }
      if (!_bConnected)
      {
        Connect();
      }
      SendCommand("CWD " + strDirName);
      if (_iReplyCode != 250)
      {
        throw new IOException(_strReply.Substring(4));
      }
      this._strRemotePath = strDirName;
    }
    #endregion

    #region 内部函数
    /// <summary>
    /// 将一行应答字符串记录在strReply和strMsg,应答码记录在iReplyCode
    /// </summary>
    private void ReadReply()
    {
      _strMsg = "";
      _strReply = ReadLine();
      _iReplyCode = Int32.Parse(_strReply.Substring(0, 3));
    }

    /// <summary>
    /// 建立进行数据连接的socket
    /// </summary>
    /// <returns>数据连接socket</returns>
    private Socket CreateDataSocket()
    {
      SendCommand("PASV");
      if (_iReplyCode != 227)
      {
        throw new IOException(_strReply.Substring(4));
      }
      int index1 = _strReply.IndexOf('(');
      int index2 = _strReply.IndexOf(')');
      string ipData = _strReply.Substring(index1 + 1, index2 - index1 - 1);
      int[] parts = new int[6];
      int len = ipData.Length;
      int partCount = 0;
      string buf = "";
      for (int i = 0; i < len && partCount <= 6; i++)
      {
        char ch = Char.Parse(ipData.Substring(i, 1));
        if (Char.IsDigit(ch))
          buf += ch;
        else if (ch != ',')
        {
          throw new IOException("Malformed PASV strReply: " + _strReply);
        }
        if (ch == ',' || i + 1 == len)
        {
          try
          {
            parts[partCount++] = Int32.Parse(buf);
            buf = "";
          }
          catch (Exception)
          {
            throw new IOException("Malformed PASV strReply: " + _strReply);
          }
        }
      }
      string ipAddress = parts[0] + "." + parts[1] + "." + parts[2] + "." + parts[3];
      int port = (parts[4] << 8) + parts[5];
      var s = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
      var ep = new IPEndPoint(IPAddress.Parse(ipAddress), port);
      try
      {
        s.Connect(ep);
      }
      catch (Exception)
      {
        throw new IOException("无法连接ftp服务器");
      }
      return s;
    }

    /// <summary>
    /// 关闭socket连接(用于登录以前)
    /// </summary>
    private void CloseSocketConnect()
    {
      lock (Obj)
      {
        if (_socketControl != null)
        {
          _socketControl.Close();
          _socketControl = null;
        }
        _bConnected = false;
      }
    }

    /// <summary>
    /// 读取Socket返回的所有字符串
    /// </summary>
    /// <returns>包含应答码的字符串行</returns>
    private string ReadLine()
    {
      lock (Obj)
      {
        while (true)
        {
          int iBytes = _socketControl.Receive(_buffer, _buffer.Length, 0);
          _strMsg += _ascii.GetString(_buffer, 0, iBytes);
          if (iBytes < _buffer.Length)
          {
            break;
          }
        }
      }
      char[] seperator = { '\n' };
      string[] mess = _strMsg.Split(seperator);
      if (_strMsg.Length > 2)
      {
        _strMsg = mess[mess.Length - 2];
      }
      else
      {
        _strMsg = mess[0];
      }
      if (!_strMsg.Substring(3, 1).Equals(" ")) //返回字符串正确的是以应答码(如220开头,后面接一空格,再接问候字符串)
      {
        return ReadLine();
      }
      return _strMsg;
    }

    /// <summary>
    /// 发送命令并获取应答码和最后一行应答字符串
    /// </summary>
    /// <param name="strCommand">命令</param>
    public void SendCommand(String strCommand)
    {
      lock (Obj)
      {
        Byte[] cmdBytes = Encoding.ASCII.GetBytes((strCommand + "\r\n").ToCharArray());
        _socketControl.Send(cmdBytes, cmdBytes.Length, 0);
        Thread.Sleep(100);
        ReadReply();
      }
    }
    #endregion
  }
}

#region 程序集 System.dll, v4.0.0.0
// C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.0\System.dll
#endregion

using System;

namespace System.Net
{
  // 摘要:
  //   System.Net.WebRequestMethods.Ftp、System.Net.WebRequestMethods.File 和 System.Net.WebRequestMethods.Http
  //   类的容器类。无法继承此类
  public static class WebRequestMethods
  {

    // 摘要:
    //   表示可用于 FILE 请求的文件协议方法的类型。无法继承此类。
    public static class File
    {
      // 摘要:
      //   表示用来从指定的位置检索文件的 FILE GET 协议方法。
      public const string DownloadFile = "GET";
      //
      // 摘要:
      //   表示用来将文件复制到指定位置的 FILE PUT 协议方法。
      public const string UploadFile = "PUT";
    }

    // 摘要:
    //   表示可与 FTP 请求一起使用的 FTP 协议方法的类型。无法继承此类。
    public static class Ftp
    {
      // 摘要:
      //   表示要用于将文件追加到 FTP 服务器上的现有文件的 FTP APPE 协议方法。
      public const string AppendFile = "APPE";
      //
      // 摘要:
      //   表示要用于删除 FTP 服务器上的文件的 FTP DELE 协议方法。
      public const string DeleteFile = "DELE";
      //
      // 摘要:
      //   表示要用于从 FTP 服务器下载文件的 FTP RETR 协议方法。
      public const string DownloadFile = "RETR";
      //
      // 摘要:
      //   表示要用于从 FTP 服务器上的文件检索日期时间戳的 FTP MDTM 协议方法。
      public const string GetDateTimestamp = "MDTM";
      //
      // 摘要:
      //   表示要用于检索 FTP 服务器上的文件大小的 FTP SIZE 协议方法。
      public const string GetFileSize = "SIZE";
      //
      // 摘要:
      //   表示获取 FTP 服务器上的文件的简短列表的 FTP NLIST 协议方法。
      public const string ListDirectory = "NLST";
      //
      // 摘要:
      //   表示获取 FTP 服务器上的文件的详细列表的 FTP LIST 协议方法。
      public const string ListDirectoryDetails = "LIST";
      //
      // 摘要:
      //   表示在 FTP 服务器上创建目录的 FTP MKD 协议方法。
      public const string MakeDirectory = "MKD";
      //
      // 摘要:
      //   表示打印当前工作目录的名称的 FTP PWD 协议方法。
      public const string PrintWorkingDirectory = "PWD";
      //
      // 摘要:
      //   表示移除目录的 FTP RMD 协议方法。
      public const string RemoveDirectory = "RMD";
      //
      // 摘要:
      //   表示重命名目录的 FTP RENAME 协议方法。
      public const string Rename = "RENAME";
      //
      // 摘要:
      //   表示将文件上载到 FTP 服务器的 FTP STOR 协议方法。
      public const string UploadFile = "STOR";
      //
      // 摘要:
      //   表示将具有唯一名称的文件上载到 FTP 服务器的 FTP STOU 协议方法。
      public const string UploadFileWithUniqueName = "STOU";
    }

    // 摘要:
    //   表示可与 HTTP 请求一起使用的 HTTP 协议方法的类型。
    public static class Http
    {
      // 摘要:
      //   表示与代理一起使用的 HTTP CONNECT 协议方法，该代理可以动态切换到隧道，如 SSL 隧道的情况。
      public const string Connect = "CONNECT";
      //
      // 摘要:
      //   表示一个 HTTP GET 协议方法。
      public const string Get = "GET";
      //
      // 摘要:
      //   表示一个 HTTP HEAD 协议方法。除了服务器在响应中只返回消息头不返回消息体以外，HEAD 方法和 GET 是一样的。
      public const string Head = "HEAD";
      //
      // 摘要:
      //   表示一个 HTTP MKCOL 请求，该请求在请求 URI（统一资源标识符）指定的位置新建集合，如页的集合。
      public const string MkCol = "MKCOL";
      //
      // 摘要:
      //   表示一个 HTTP POST 协议方法，该方法用于将新实体作为补充发送到某个 URI。
      public const string Post = "POST";
      //
      // 摘要:
      //   表示一个 HTTP PUT 协议方法，该方法用于替换 URI 标识的实体。
      public const string Put = "PUT";
    }
  }
}