ftp_get_file_and_directory

        class DirectoryItem
        {
            public Uri BaseUri;
            public string AbsolutePath
            { get { return string.Format("{0}/{1}", BaseUri, Name); } }
            public DateTime DateCreated;
            public bool IsDirectory;
            public string Name;
            public List<DirectoryItem> Items;
            public override string ToString() { return Name; }
        }

        internal enum enumFolderListFMT { UNIX, DOS_IIS };
        internal enum enumFTPPlatform { WindowsServer2008, ServU}
        /// <summary>
        /// 获取目录信息（包含文件夹，文件）
        /// </summary>
        /// <param name="address"></param>
        /// <param name="username"></param>
        /// <param name="password"></param>
        /// <returns></returns>
        static List<DirectoryItem> GetDirectoryInformation(string addr2, string username, string password)
        {
            var address = addr2.EndsWith("/") ? addr2.Substring(0, addr2.Length - 1) : addr2;//去除最后一个斜杠
            FtpWebRequest request = (FtpWebRequest)FtpWebRequest.Create(address);
            request.Method = WebRequestMethods.Ftp.ListDirectoryDetails;
            request.Credentials = new NetworkCredential(username, password);
            request.UsePassive = true;
            request.UseBinary = true;
            request.KeepAlive = false;

            string[] list = null;
            using (FtpWebResponse response = (FtpWebResponse)request.GetResponse())
            using (StreamReader reader = new StreamReader(response.GetResponseStream()))
            {
                list = reader.ReadToEnd().Split(new string[] { "\r\n" }, StringSplitOptions.RemoveEmptyEntries);
            }

            //unix or dos_iis format?
            enumFolderListFMT folderFormat = enumFolderListFMT.UNIX;
            int dir_pos = 0;
            bool found = false;
            foreach (var item in list)
            {
                if (item.ToLower().Contains("<dir>"))
                {
                    folderFormat = enumFolderListFMT.DOS_IIS;
                    dir_pos = item.ToLower().IndexOf("<dir>");
                    found = true;
                    break;
                }
            }
            if (!found && list.Length > 0 && list[0].ToLower()[0] != ‘d‘ && list[0].ToLower()[0] != ‘-‘)
            {
                folderFormat = enumFolderListFMT.DOS_IIS;
            }

            enumFTPPlatform ftpPlatform = enumFTPPlatform.WindowsServer2008;
            if (folderFormat == enumFolderListFMT.UNIX)
            {
                if (list.Length > 0 && list[0].Substring(0, 10).ToLower().Count(c => c == ‘-‘) < 3)
                    ftpPlatform = enumFTPPlatform.WindowsServer2008;
                else
                    ftpPlatform = enumFTPPlatform.ServU;
            }

            List<DirectoryItem> returnValue = new List<DirectoryItem>();
            if (folderFormat == enumFolderListFMT.DOS_IIS)
            {
                foreach (var item in list)
                {
                    if (item.ToLower().Contains("<dir>"))
                    {
                        var dir = item.Substring(dir_pos + 5).Trim();
                        if (dir == "." || dir == "..") continue;

                        var di = new DirectoryItem();
                        di.BaseUri = new Uri(address);
                        //di.DateCreated = dateTime;
                        di.IsDirectory = true;
                        di.Name = dir;
                        //Debug.WriteLine(di.AbsolutePath);
                        di.Items = GetDirectoryInformation(di.AbsolutePath, username, password);
                        returnValue.Add(di);
                    }
                    else
                    {
                        string filename = "";
                        if(found)
                            filename = item.Substring(dir_pos + 14).Trim();
                        else
                            filename = item.Substring(39).Trim();
                        var di = new DirectoryItem();
                        di.BaseUri = new Uri(address);
                        di.IsDirectory = false;
                        di.Name = filename;
                        di.Items = null;
                        returnValue.Add(di);
                    }
                }
            }
            else if (folderFormat == enumFolderListFMT.UNIX)
            {
                var pos = ftpPlatform == enumFTPPlatform.WindowsServer2008 ? 58 : 54;
                foreach (var item in list)
                {
                    if (item.Substring(0, 1).ToLower() == "d")
                    {
                        var dir = item.Substring(pos).Trim();
                        if (dir == "." || dir == "..") continue;
                        var di = new DirectoryItem();
                        di.BaseUri = new Uri(address);
                        di.IsDirectory = true;
                        di.Name = dir;
                        di.Items = GetDirectoryInformation(di.AbsolutePath, username, password);
                        returnValue.Add(di);
                    }
                    else if (item.Substring(0, 1).ToLower() == "-")
                    {
                        var filename = item.Substring(pos).Trim();
                        var di = new DirectoryItem();
                        di.BaseUri = new Uri(address);
                        di.IsDirectory = false;
                        di.Name = filename;
                        di.Items = null;
                        returnValue.Add(di);
                    }
                }
            }
            return returnValue;
        }

        /// <summary>
        /// 下载文件
        /// </summary>
        /// <param name="filePath">下载到哪里</param>
        /// <param name="outputFilename">下载后的文件名</param>
        /// <param name="fileName">服务器上的文件名</param>
        /// <param name="ftpServerIP">服务器全路径，注意最后的斜线不可少。如ftp://172.18.1.152:8009/aaa/</param>
        /// <param name="ftpUserID">访问的用户名</param>
        /// <param name="ftpPassword">访问的密码</param>
        /// <returns></returns>
        public int DownloadFile(string filePath, string outputFilename, string fileName, string ftpServerIP, string ftpUserID, string ftpPassword)
        {
            FtpWebRequest reqFTP;
            try
            {
                //filePath = < <The full path where the file is to be created.>>,
                //fileName = < <Name of the file to be created(Need not be the name of the file on FTP server).>>
                FileStream outputStream = new FileStream(filePath + "\\" + outputFilename, FileMode.Create);

                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpServerIP + fileName));
                reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;
                reqFTP.UseBinary = true;
                reqFTP.KeepAlive = false;
                reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
                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();
                return 0;
            }
            catch (Exception ex)
            {
                // Logging.WriteError(ex.Message + ex.StackTrace);
                System.Windows.Forms.MessageBox.Show(ex.Message);
                return -2;
            }
        }

get_directory_file_download