public class FtpOperation    {        public static void UploadFile(FileInfo fileinfo, string targetDir, string hostname, string username, string password, string reName)        {            //1. check target            string target;            if (targetDir.Trim() == "")            {                return;            }            target = Guid.NewGuid().ToString(); //使用临时文件名            string URI = "FTP://" + hostname + "/" + targetDir + "/" + target;            ///WebClient webcl = new WebClient();            System.Net.FtpWebRequest ftp = GetRequest(URI, username, password);            //设置FTP命令 设置所要执行的FTP命令，            //ftp.Method = System.Net.WebRequestMethods.Ftp.ListDirectoryDetails;//假设此处为显示指定路径下的文件列表            ftp.Method = System.Net.WebRequestMethods.Ftp.UploadFile;            //指定文件传输的数据类型            ftp.UseBinary = true;            ftp.UsePassive = true;            //告诉ftp文件大小            ftp.ContentLength = fileinfo.Length;            //缓冲大小设置为2KB            const int BufferSize = 2048;            byte[] content = new byte[BufferSize - 1 + 1];            int dataRead;            //打开一个文件流 (System.IO.FileStream) 去读上传的文件            using (FileStream fs = fileinfo.OpenRead())            {                try                {                    //把上传的文件写入流                    using (Stream rs = ftp.GetRequestStream())                    {                        do                        {                            //每次读文件流的2KB                            dataRead = fs.Read(content, 0, BufferSize);                            rs.Write(content, 0, dataRead);                        } while (!(dataRead < BufferSize));                        rs.Close();                    }                }                catch (Exception ex) { }                finally                {                    fs.Close();                }            }            ftp = null;            //设置FTP命令            ftp = GetRequest(URI, username, password);            ftp.Method = System.Net.WebRequestMethods.Ftp.Rename; //改名            ftp.RenameTo = reName;            //ftp.RenameTo = fileinfo.Name;            try            {                ftp.GetResponse();            }            catch (Exception ex)            {                ftp = GetRequest(URI, username, password);                ftp.Method = System.Net.WebRequestMethods.Ftp.DeleteFile; //删除                ftp.GetResponse();                throw ex;            }            finally            {                //fileinfo.Delete();            }            // 可以记录一个日志 "上传" + fileinfo.FullName + "上传到" + "FTP://" + hostname + "/" + targetDir + "/" + fileinfo.Name + "成功." );            ftp = null;            #region            /******FtpWebResponse* ****/            //FtpWebResponse ftpWebResponse = (FtpWebResponse)ftp.GetResponse();            #endregion        }        public static  void Download(string filePath, string fileName, string ftpServerIP, string ftpUser, string ftpPwd)        {            FtpWebRequest reqFTP;            try            {                //filePath = <
     
      >,                //fileName = <
      
       >                FileStream outputStream = new FileStream(filePath + "\\" + fileName, FileMode.Create);                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + ftpServerIP + "/" + fileName));                reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;                reqFTP.UseBinary = true;                reqFTP.Credentials = new NetworkCredential(ftpUser, ftpPwd);                FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();                Stream ftpStream = response.GetResponseStream();                long cl = response.ContentLength;                int bufferSize = 2048;                int readCount;                byte[] buffer = new byte[bufferSize];                readCount = ftpStream.Read(buffer, 0, bufferSize);                while (readCount > 0)                {                    outputStream.Write(buffer, 0, readCount);                    readCount = ftpStream.Read(buffer, 0, bufferSize);                }                ftpStream.Close();                outputStream.Close();                response.Close();            }            catch (Exception ex)            {                MessageBox.Show(ex.Message);            }        }        public static string GetStringResponse(FtpWebRequest ftp)        {            //Get the result, streaming to a string            string result = "";            using (FtpWebResponse response = (FtpWebResponse)ftp.GetResponse())            {                long size = response.ContentLength;                using (Stream datastream = response.GetResponseStream())                {                    using (StreamReader sr = new StreamReader(datastream, System.Text.Encoding.Default))                    {                        result = sr.ReadToEnd();                        sr.Close();                    }                    datastream.Close();                }                response.Close();            }            return result;        }        public static FtpWebRequest GetRequest(string URI, string username, string password)        {            //根据服务器信息FtpWebRequest创建类的对象            FtpWebRequest result = (FtpWebRequest)FtpWebRequest.Create(URI);            //提供身份验证信息            result.Credentials = new System.Net.NetworkCredential(username, password);            //设置请求完成之后是否保持到FTP服务器的控制连接，默认值为true            result.KeepAlive = true;            return result;        }    }