C# ftp 下载文件

public string Download(string userId, string pwd, string ftpPath, string filePath, string fileName)
        {
            string sRet = "下载成功！";
            FtpWebRequest reqFTP;
            try
            {
                FileStream outputStream = new FileStream(filePath + fileName, FileMode.Create);
                // 根据uri创建FtpWebRequest对象     
                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpPath + fileName));
                // 指定执行什么命令    
                reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;

                // 指定数据传输类型    
                reqFTP.UseBinary = true;
                reqFTP.UsePassive = false;

                // ftp用户名和密码    
                reqFTP.Credentials = new NetworkCredential(userId, pwd);
                FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();

                // 把下载的文件写入流  
                Stream ftpStream = response.GetResponseStream();
                long cl = response.ContentLength;

                // 缓冲大小设置为2kb    
                int bufferSize = 2048;
                int readCount;
                byte[] buffer = new byte[bufferSize];

                // 每次读文件流的2kb    
                readCount = ftpStream.Read(buffer, 0, bufferSize);
                while (readCount > 0)
                {
                    // 把内容从文件流写入     
                    outputStream.Write(buffer, 0, readCount);
                    readCount = ftpStream.Read(buffer, 0, bufferSize);
                }

                //关闭两个流和ftp连接  
                ftpStream.Close();
                outputStream.Close();
                response.Close();
            }
            catch (Exception ex)
            {
                sRet = ex.Message;
            }

            //返回下载结果（是否下载成功）  
            return sRet;
        }   

调用：

Download("ftpuserName", "ftpuserPass", @"ftp://192.168.1.12/", @"d://", "20140108.txt.rar");