分享用于操作FTP的客户端C#类

using System;using System.Net;using System.IO;using System.Text;using System.Net.Sockets;using System.Threading; namespace DotNet.Utilities{  public class FTPClient  {    public static object obj = new object();     #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>    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 字段    private int strRemotePort;    private Boolean bConnected;    private string strRemoteHost;    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 static int BLOCK_SIZE = 512;    /// <summary>    /// 编码方式    /// </summary>    Encoding ASCII = Encoding.ASCII;    /// <summary>    /// 字节数组    /// </summary>    Byte[] buffer = new Byte[BLOCK_SIZE];    #endregion     #region 属性    /// <summary>    /// FTP服务器IP地址    /// </summary>    public string RemoteHost    {      get      {        return strRemoteHost;      }      set      {        strRemoteHost = value;      }    }     /// <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);        IPEndPoint 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)    {      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>    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("//"));      string strTypeName = strFileName.Substring(strFileName.LastIndexOf("."));      strGuid = str + "//" + strGuid;      Socket socketData = CreateDataSocket();      SendCommand("STOR " + Path.GetFileName(strGuid));      if (!(iReplyCode == 125 || iReplyCode == 150))      {        throw new IOException(strReply.Substring(4));      }      FileStream input = new FileStream(strGuid, FileMode.Open);      input.Flush();      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));        }      }    }     /// <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 = 0;      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);      string strResult = "";      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();      strResult = System.Text.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));        }        FileStream 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();        socketData = null;        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));      }      FileStream 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));      }       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));        }      }    }      /// <summary>    /// 上传一个文件    /// </summary>    /// <param name="strFileName">本地文件名</param>    public void PutByGuid(string strFileName, string strGuid)    {      if (!bConnected)      {        Connect();      }      string str = strFileName.Substring(0, strFileName.LastIndexOf("//"));      string strTypeName = strFileName.Substring(strFileName.LastIndexOf("."));      strGuid = str + "//" + strGuid;      System.IO.File.Copy(strFileName, strGuid);      System.IO.File.SetAttributes(strGuid, System.IO.FileAttributes.Normal);      Socket socketData = CreateDataSocket();      SendCommand("STOR " + Path.GetFileName(strGuid));      if (!(iReplyCode == 125 || iReplyCode == 150))      {        throw new IOException(strReply.Substring(4));      }      FileStream 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];      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("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(500);        ReadReply();      }    }    #endregion  }}

using System;using System.Net;using System.IO;using System.Text;using System.Net.Sockets;namespace FtpLib{public class FTPFactory{  private string  remoteHost, remotePath, remoteUser, remotePass, mes;  private int remotePort, bytes;  private Socket clientSocket;  private int retValue;  private Boolean debug;  private Boolean logined;  private string reply;  private static int BLOCK_SIZE = 512;  Byte[] buffer = new Byte[BLOCK_SIZE];  Encoding ASCII = Encoding.ASCII;  public FTPFactory()  {    remoteHost = "localhost";    remotePath = ".";    remoteUser = "anonymous";    remotePass = "";    remotePort = 21;    debug = false;    logined = false;  }  ///  /// Set the name of the FTP server to connect to.  ///  /// Server name  public void setRemoteHost(string remoteHost)  {    this.remoteHost = remoteHost;  }  ///  /// Return the name of the current FTP server.  ///  /// Server name  public string getRemoteHost()  {    return remoteHost;  }  ///  /// Set the port number to use for FTP.  ///  /// Port number  public void setRemotePort(int remotePort)  {    this.remotePort = remotePort;  }  ///  /// Return the current port number.  ///  /// Current port number  public int getRemotePort()  {    return remotePort;  }  ///  /// Set the remote directory path.  ///  /// The remote directory path  public void setRemotePath(string remotePath)  {    this.remotePath = remotePath;  }  ///  /// Return the current remote directory path.  ///  /// The current remote directory path.  public string getRemotePath()  {    return remotePath;  }  ///  /// Set the user name to use for logging into the remote server.  ///  /// Username  public void setRemoteUser(string remoteUser)  {    this.remoteUser = remoteUser;  }  ///  /// Set the password to user for logging into the remote server.  ///  /// Password  public void setRemotePass(string remotePass)  {    this.remotePass = remotePass;  }  ///  /// Return a string array containing the remote directory's file list.  ///  ///  ///  public string[] getFileList(string mask)  {    if (!logined)    {      login();    }    Socket cSocket = createDataSocket();    sendCommand("NLST " + mask);    if (!(retValue == 150 || retValue == 125))    {      throw new IOException(reply.Substring(4));    }    mes = "";    while (true)    {      int bytes = cSocket.Receive(buffer, buffer.Length, 0);      mes += ASCII.GetString(buffer, 0, bytes);      if (bytes < buffer.Length)      {        break;      }    }    char[] seperator = { '/n' };    string[] mess = mes.Split(seperator);    cSocket.Close();    readReply();    if (retValue != 226)    {      throw new IOException(reply.Substring(4));    }    return mess;  }  ///  /// Return the size of a file.  ///  ///  ///  public long getFileSize(string fileName)  {    if (!logined)    {      login();    }    sendCommand("SIZE " + fileName);    long size = 0;    if (retValue == 213)    {      size = Int64.Parse(reply.Substring(4));    }    else    {      throw new IOException(reply.Substring(4));    }    return size;  }  ///  /// Login to the remote server.  ///  public void login()  {    clientSocket = new    Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);    IPEndPoint ep = new    IPEndPoint(Dns.Resolve(remoteHost).AddressList[0], remotePort);    try    {      clientSocket.Connect(ep);    }    catch (Exception)    {      throw new IOException("Couldn't connect to remote server");    }    readReply();    if (retValue != 220)    {      close();      throw new IOException(reply.Substring(4));    }    if (debug)      Console.WriteLine("USER " + remoteUser);    sendCommand("USER " + remoteUser);    if (!(retValue == 331 || retValue == 230))    {      cleanup();      throw new IOException(reply.Substring(4));    }    if (retValue != 230)    {      if (debug)        Console.WriteLine("PASS xxx");      sendCommand("PASS " + remotePass);      if (!(retValue == 230 || retValue == 202))      {        cleanup();        throw new IOException(reply.Substring(4));      }    }    logined = true;    Console.WriteLine("Connected to " + remoteHost);    chdir(remotePath);  }  ///  /// If the value of mode is true, set binary mode for downloads.  /// Else, set Ascii mode.  ///  ///  public void setBinaryMode(Boolean mode)  {    if (mode)    {      sendCommand("TYPE I");    }    else    {      sendCommand("TYPE A");    }    if (retValue != 200)    {      throw new IOException(reply.Substring(4));    }  }  ///  /// Download a file to the Assembly's local directory,  /// keeping the same file name.  ///  ///  public void download(string remFileName)  {    download(remFileName, "", false);  }  ///  /// Download a remote file to the Assembly's local directory,  /// keeping the same file name, and set the resume flag.  ///  ///  ///  public void download(string remFileName, Boolean resume)  {    download(remFileName, "", resume);  }  ///  /// Download a remote file to a local file name which can include  /// a path. The local file name will be created or overwritten,  /// but the path must exist.  ///  ///  ///  public void download(string remFileName, string locFileName)  {    download(remFileName, locFileName, false);  }  ///  /// Download a remote file to a local file name which can include  /// a path, and set the resume flag. The local file name will be  /// created or overwritten, but the path must exist.  ///  ///  ///  ///  public void download(string remFileName, string  locFileName, Boolean resume)  {    if (!logined)    {      login();    }    setBinaryMode(true);    Console.WriteLine("Downloading file " + remFileName + " from " + remoteHost + "/" + remotePath);    if (locFileName.Equals(""))    {      locFileName = remFileName;    }    if (!File.Exists(locFileName))    {      Stream st = File.Create(locFileName);      st.Close();    }    FileStream output = new    FileStream(locFileName, FileMode.Open);    Socket cSocket = createDataSocket();    long offset = 0;    if (resume)    {      offset = output.Length;      if (offset > 0)      {        sendCommand("REST " + offset);        if (retValue != 350)        {          //throw new IOException(reply.Substring(4));          //Some servers may not support resuming.          offset = 0;        }      }      if (offset > 0)      {        if (debug)        {          Console.WriteLine("seeking to " + offset);        }        long npos = output.Seek(offset, SeekOrigin.Begin);        Console.WriteLine("new pos=" + npos);      }    }    sendCommand("RETR " + remFileName);    if (!(retValue == 150 || retValue == 125) )    {      throw new IOException(reply.Substring(4));    }    while (true)    {      bytes = cSocket.Receive(buffer, buffer.Length, 0);      output.Write(buffer, 0, bytes);      if (bytes <= 0)      {        break;      }    }    output.Close();    if (cSocket.Connected)    {      cSocket.Close();    }    Console.WriteLine("");    readReply();    if (!(retValue == 226 || retValue == 250))    {      throw new IOException(reply.Substring(4));    }  }  ///  /// Upload a file.  ///  ///  public void upload(string fileName)  {    upload(fileName, false);  }  ///  /// Upload a file and set the resume flag.  ///  ///  ///  public void upload(string fileName, Boolean resume)  {    if (!logined)    {      login();    }    Socket cSocket = createDataSocket();    long offset = 0;    if (resume)    {      try      {        setBinaryMode(true);        offset = getFileSize(fileName);      }      catch (Exception)      {        offset = 0;      }    }    if (offset > 0)    {      sendCommand("REST " + offset);      if (retValue != 350)      {        //throw new IOException(reply.Substring(4));        //Remote server may not support resuming.        offset = 0;      }    }    sendCommand("STOR " + Path.GetFileName(fileName));    if (!(retValue == 125 || retValue == 150))    {      throw new IOException(reply.Substring(4));    }    // open input stream to read source file    FileStream input = new    FileStream(fileName, FileMode.Open);    if (offset != 0)    {      if (debug)      {        Console.WriteLine("seeking to " + offset);      }      input.Seek(offset, SeekOrigin.Begin);    }    Console.WriteLine("Uploading file " + fileName + " to " + remotePath);    while ((bytes = input.Read(buffer, 0, buffer.Length)) > 0)    {      cSocket.Send(buffer, bytes, 0);    }    input.Close();    Console.WriteLine("");    if (cSocket.Connected)    {      cSocket.Close();    }    readReply();    if (!(retValue == 226 || retValue == 250))    {      throw new IOException(reply.Substring(4));    }  }  ///  /// Delete a file from the remote FTP server.  ///  ///  public void deleteRemoteFile(string fileName)  {    if (!logined)    {      login();    }    sendCommand("DELE " + fileName);    if (retValue != 250)    {      throw new IOException(reply.Substring(4));    }  }  ///  /// Rename a file on the remote FTP server.  ///  ///  ///  public void renameRemoteFile(string oldFileName, string  newFileName)  {    if (!logined)    {      login();    }    sendCommand("RNFR " + oldFileName);    if (retValue != 350)    {      throw new IOException(reply.Substring(4));    }    // known problem    // rnto will not take care of existing file.    // i.e. It will overwrite if newFileName exist    sendCommand("RNTO " + newFileName);    if (retValue != 250)    {      throw new IOException(reply.Substring(4));    }  }  ///  /// Create a directory on the remote FTP server.  ///  ///  public void mkdir(string dirName)  {    if (!logined)    {      login();    }    sendCommand("MKD " + dirName);    if (retValue != 257)    {      throw new IOException(reply.Substring(4));    }  }  ///  /// Delete a directory on the remote FTP server.  ///  ///  public void rmdir(string dirName)  {    if (!logined)    {      login();    }    sendCommand("RMD " + dirName);    if (retValue != 250)    {      throw new IOException(reply.Substring(4));    }  }  ///  /// Change the current working directory on the remote FTP server.  ///  ///  public void chdir(string dirName)  {    if (dirName.Equals("."))    {      return;    }    if (!logined)    {      login();    }    sendCommand("CWD " + dirName);    if (retValue != 250)    {      throw new IOException(reply.Substring(4));    }    this.remotePath = dirName;    Console.WriteLine("Current directory is " + remotePath);  }  ///  /// Close the FTP connection.  ///  public void close()  {    if (clientSocket != null)    {      sendCommand("QUIT");    }    cleanup();    Console.WriteLine("Closing...");  }  ///  /// Set debug mode.  ///  ///  public void setDebug(Boolean debug)  {    this.debug = debug;  }  private void readReply()  {    mes = "";    reply = readLine();    retValue = Int32.Parse(reply.Substring(0, 3));  }  private void cleanup()  {    if (clientSocket != null)    {      clientSocket.Close();      clientSocket = null;    }    logined = false;  }  private string readLine()  {    while (true)    {      bytes = clientSocket.Receive(buffer, buffer.Length, 0);      mes += ASCII.GetString(buffer, 0, bytes);      if (bytes < buffer.Length)      {        break;      }    }    char[] seperator = { '/n' };    string[] mess = mes.Split(seperator);    if (mes.Length > 2)    {      mes = mess[mess.Length - 2];    }    else    {      mes = mess[0];    }    if (!mes.Substring(3, 1).Equals(" "))    {      return readLine();    }    if (debug)    {      for (int k = 0; k < mess.Length - 1; k++)      {        Console.WriteLine(mess[k]);      }    }    return mes;  }  private void sendCommand(String command)  {    Byte[] cmdBytes =      //Encoding.ASCII.GetBytes((command + "/r/n").ToCharArray());    Encoding.Default.GetBytes((command + "/r/n").ToCharArray());     clientSocket.Send(cmdBytes, cmdBytes.Length, 0);    readReply();  }  private Socket createDataSocket()  {    sendCommand("PASV");    if (retValue != 227)    {      throw new IOException(reply.Substring(4));    }    int index1 = reply.IndexOf('(');    int index2 = reply.IndexOf(')');    string ipData =    reply.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 reply: " +        reply);      }      if (ch == ',' || i + 1 == len)      {        try        {          parts[partCount++] = Int32.Parse(buf);          buf = "";        }        catch (Exception)        {          throw new IOException("Malformed PASV reply: " +          reply);        }      }    }    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(Dns.Resolve(ipAddress).AddressList[0], port);    try    {      s.Connect(ep);    }    catch (Exception)    {      throw new IOException("Can't connect to remote server");    }    return s;  }}}