using System;
 using ;
 using System.IO;
 using System.Text;
 using .Sockets;
 namespace FTP_GET_PUT
 { 
 
  /// <summary>
  /// FTPClient 的摘要说明。
  /// </summary>
  public class FTPClient
  { 
 
   #region 构造函数
   /// <summary>
   /// 缺省构造函数
   /// </summary>
   public FTPClient()
   { 
 
    strRemoteHost  = "";
    strRemotePath  = "";
    strRemoteUser  = "";
    strRemotePass  = "";
    strRemotePort  = 21;
    bConnected     = false;
   }
   /// <summary>
   /// 构造函数
   /// </summary>
   /// <param name="remoteHost"></param>
   /// <param name="remotePath"></param>
   /// <param name="remoteUser"></param>
   /// <param name="remotePass"></param>
   /// <param name="remotePort"></param>
   public FTPClient(string remoteHost, string remotePath, string remoteUser, string remotePass, int remotePort )
   { 
 
    strRemoteHost  = remoteHost;
    strRemotePath  = remotePath;
    strRemoteUser  = remoteUser;
    strRemotePass  = remotePass;
    strRemotePort  = remotePort;
    Connect();
   }
   #endregion
   #region 登陆
   /// <summary>
   /// FTP服务器IP地址
   /// </summary>
   private string strRemoteHost;
   public string RemoteHost
   { 
 
    get
    { 
 
     return strRemoteHost;
    }
    set
    { 
 
     strRemoteHost = value;
    }
   }
   /// <summary>
   /// FTP服务器端口
   /// </summary>
   private int strRemotePort;
   public int RemotePort
   { 
 
    get
    { 
 
     return strRemotePort;
    }
    set
    { 
 
     strRemotePort = value;
    }
   }
   /// <summary>
   /// 当前服务器目录
   /// </summary>
   private string strRemotePath;
   public string RemotePath
   { 
 
    get
    { 
 
     return strRemotePath;
    }
    set
    { 
 
     strRemotePath = value;
    }
   }
   /// <summary>
   /// 登录用户账号
   /// </summary>
   private string strRemoteUser;
   public string RemoteUser
   { 
 
    set
    { 
 
     strRemoteUser = value;
    }
   }
   /// <summary>
   /// 用户登录密码
   /// </summary>
   private string strRemotePass;
   public string RemotePass
   { 
 
    set
    { 
 
     strRemotePass = value;
    }
   }
   /// <summary>
   /// 是否登录
   /// </summary>
   private Boolean bConnected;
   public bool Connected
   { 
 
    get
    { 
 
     return bConnected;
    }
   }
   #endregion
   #region 链接
   /// <summary>
   /// 建立连接 
   /// </summary>
   public void Connect()
   { 
 
    socketControl = new Socket(AddressFamily.InterNetwork,SocketType.Stream,ProtocolType.Tcp);
    IPEndPoint ep = new IPEndPoint(IPAddress.Parse(RemoteHost), strRemotePort);
    // 链接
    try
    { 
 
     socketControl.Connect(ep);
    }
    catch(Exception)
    { 
 
     throw new IOException("Couldn't connect to remote server");
    }
    // 获取应答码
    ReadReply();
    if(iReplyCode != 220)
    { 
 
     DisConnect();
     throw new IOException(strReply.Substring(4));
    }
    // 登陆
    SendCommand("USER "+strRemoteUser);
    if( !(iReplyCode == 331 || iReplyCode == 230) )
    { 
 
     CloseSocketConnect();//关闭连接
     throw new IOException(strReply.Substring(4));
    }
    if( iReplyCode != 230 )
    { 
 
     SendCommand("PASS "+strRemotePass);
     if( !(iReplyCode == 230 || iReplyCode == 202) )
     { 
 
      CloseSocketConnect();//关闭连接
      throw new IOException(strReply.Substring(4));
     }
    }
    bConnected = true;
    // 切换到目录
    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)
   { 
 
    if(ttType == TransferType.Binary)
    { 
 
     SendCommand("TYPE I");//binary类型传输
    }
    else
    { 
 
     SendCommand("TYPE A");//ASCII类型传输
    }
    if (iReplyCode != 200)
    { 
 
     throw new IOException(strReply.Substring(4));
    }
    else
    { 
 
     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>
   /// <returns></returns>
   public string[] Dir(string strMask)
   { 
 
    // 建立链接
    if(!bConnected)
    { 
 
     Connect();
    }
    //建立进行数据连接的socket
    Socket socketData = CreateDataSocket();
    
    //传送命令
    SendCommand("NLST " + strMask);
    //分析应答代码
    if(!(iReplyCode == 150 || iReplyCode == 125 || iReplyCode == 226))
    { 
 
     throw new IOException(strReply.Substring(4));
    }
    //获得结果
    strMsg = "";
    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;
   }
     
   /// <summary>
   /// 获取文件大小
   /// </summary>
   /// <param name="strFileName">文件名</param>
   /// <returns>文件大小</returns>
   private long GetFileSize(string strFileName)
   { 
 
    if(!bConnected)
    { 
 
     Connect();
    }
    SendCommand("SIZE " + Path.GetFileName(strFileName));
    long lSize=0;
    if(iReplyCode == 213)
    { 
 
     lSize = Int64.Parse(strReply.Substring(4));
    }
    else
    { 
 
     throw new IOException(strReply.Substring(4));
    }
    return lSize;
   }  /// <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)
   { 
 
    if(!bConnected)
    { 
 
     Connect();
    }
    SetTransferType(TransferType.Binary);
    if (strLocalFileName.Equals(""))
    { 
 
     strLocalFileName = strRemoteFileName;
    }
    if(!File.Exists(strLocalFileName))
    { 
 
     Stream st = File.Create(strLocalFileName);
     st.Close();
    }
    FileStream output = new 
     FileStream(strFolder + "\\" + strLocalFileName,FileMode.Create);
    Socket socketData = CreateDataSocket();
    SendCommand("RETR " + strRemoteFileName);
    if(!(iReplyCode == 150 || iReplyCode == 125
     || iReplyCode == 226 || iReplyCode == 250))
    { 
 
     throw new IOException(strReply.Substring(4));
    }
    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)
    { 
 
     //strFile是完整的文件名(包含路径)
     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();
    SendCommand("STOR "+Path.GetFileName(strFileName));
    if( !(iReplyCode == 125 || iReplyCode == 150) )
    { 
 
     throw new IOException(strReply.Substring(4));
    }
    FileStream input = new 
     FileStream(strFileName,FileMode.Open);
    int iBytes = 0;
    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));
     }
    }
   }
     
   #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 内部变量
   /// <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 static int BLOCK_SIZE = 512;
   Byte[] buffer = new Byte[BLOCK_SIZE];
   /// <summary>
   /// 编码方式
   /// </summary>
   Encoding ASCII = Encoding.ASCII;
   #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];
    Socket s = new 
     Socket(AddressFamily.InterNetwork,SocketType.Stream,ProtocolType.Tcp);
    IPEndPoint ep = new 
     IPEndPoint(IPAddress.Parse(ipAddress), port);
    try
    { 
 
     s.Connect(ep);
    }
    catch(Exception)
    { 
 
     throw new IOException("Can't connect to remote server");
    }
    return s;
   }  /// <summary>
   /// 关闭socket连接(用于登录以前)
   /// </summary>
   private void CloseSocketConnect()
   { 
 
    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()
   { 
 
    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];
     //seperator[0]是10,换行符是由13和0组成的,分隔后10后面虽没有字符串,
     //但也会分配为空字符串给后面(也是最后一个)字符串数组,
     //所以最后一个mess是没用的空字符串
     //但为什么不直接取mess[0],因为只有最后一行字符串应答码与信息之间有空格
    }
    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>
   private void SendCommand(String strCommand)
   { 
 
    Byte[] cmdBytes = 
     Encoding.ASCII.GetBytes((strCommand+"\r\n").ToCharArray());
    socketControl.Send(cmdBytes, cmdBytes.Length, 0);
    ReadReply();
   }
   #endregion
  }
 }

下载程序:

private void btnDownLoad_Click(object sender, System.EventArgs e)
   { 
 
    ftpC.RemoteHost="192.168.1.116";
    ftpC.RemotePass="password123#";
    ftpC.RemotePath="txtFile";
    ftpC.RemotePort=21;
    ftpC.RemoteUser="administrator";
    ftpC.Connect();
    ftpC.Get("TXT.txt","F:\\TXTF","xx.txt");//将服务器中的TXT.txt文件,下载到本地F:/TXTF下并命名xx.txt
 }


上传程序:

private void btnUpLoad_Click(object sender, System.EventArgs e)
   { 
 
    ftpC.RemoteHost="192.168.1.116";
    ftpC.RemotePass="password123#";
    ftpC.RemotePath="txtFile";
    ftpC.RemotePort=21;
    ftpC.RemoteUser="administrator";
    ftpC.Connect();
    ftpC.Put("F:\\TXTF","xx.txt");//文件夹TXTF中文件xx.txt上传到服务器中
 }