C#Ftp的下载实例

public  class FTPClient
    {
      private  string ftpServerIP="";//下载的ip
      private string ftpUserID="";  //用户名
      private string ftpPassword=""; //密码
      //带参的构造函数
      public FTPClient(string ftpServerIP, string ftpUserID, string ftpPassword) 
      {
        this.ftpPassword=ftpPassword;
        this.ftpUserID = ftpUserID;
        this.ftpServerIP = ftpServerIP;
      }
      /// <summary>
      /// 下载的方法
      /// </summary>
      /// <param name="filePath">要下载的路径</param>
      /// <param name="fileName">要下载的文件名，如果为空，则代表文件下的全部文件</param>
      public  void Download(string filePath, string fileName)
      {
          FtpWebRequest reqFTP;

          try
          {
              FileStream outputStream = new FileStream(filePath + "\\" + fileName, FileMode.Create);    //文件流暑促文件

              reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + ftpServerIP + "/" + fileName)); //创建ftpWebRequest

              reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;           //ftp的方法，上传还是下载

              reqFTP.UseBinary = true;              //是否使用二进制

              reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);   //输入用户名和密码

              FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();

              Stream ftpStream = response.GetResponseStream();  //获取文件流

              long cl = response.ContentLength; //文件流的长度

              int bufferSize = 2048;

              int readCount;

              byte[] buffer = new byte[bufferSize]; //字节转换

              readCount = ftpStream.Read(buffer, 0, bufferSize);   
   
                  while (readCount > 0)
                  {
                      outputStream.Write(buffer, 0, readCount);

                      readCount = ftpStream.Read(buffer, 0, bufferSize); //读取文件
                  }
              
              ftpStream.Close();
              outputStream.Close();
              response.Close();
              System.GC.Collect();
          }
          catch (Exception ex)
          {
            //  MessageBox.Show(ex.Message);
          }
      }
    }

上面是FTp的后台服务端，下面是应用客户端：

ftpServerIP = "192.168.2.211/Test/ssl/Image";
            ftpUserID = "123456";
            ftpPassword = "123456";
            FTPClient ftpClient = new FTPClient(ftpServerIP, ftpUserID, ftpPassword);
            ftpClient.Download(@"C:\picture", "3201.png");

客户端可以输入ip,用户名，密码，要下载的路径或者有下载的文件，就可以执行了。如果下载文件为空，则代表下载ip底下的所有文件。