/// <summary>
        /// 从文件载入
        /// </summary>
        /// <param name="fileName"></param>
        public void LoadFromFile(string fileName)
        {
            FileStream   fs = new FileStream(fileName, FileMode.Open);
            StreamReader sr = new StreamReader(fs);

            try
            {
                string context = sr.ReadToEnd();

                Encrypt ept = new Encrypt(EncryptKey, false);
                context = ept.DecryptStr(context);

                Dictionary <string, ServerInfo> serCfg = DictionaryJsonHelper.DeserializeStringToDictionary <string, ServerInfo>(context);

                foreach (ServerInfo si in serCfg.Values)
                {
                    Add(si);
                }
            }
            finally
            {
                sr.Close();
                fs.Close();
            }
        }
        /// <summary>
        /// 保存到文件
        /// </summary>
        /// <param name="fileName"></param>
        public void SaveToFile(string fileName)
        {
            Dictionary <string, ServerInfo> serCfg = this.ToDictionary(key => key.ServerAlias, value => value);

            string context = DictionaryJsonHelper.SerializeDictionaryToJsonString <string, ServerInfo>(serCfg);

            FileStream   fs = new FileStream(fileName, FileMode.Create);
            StreamWriter sw = new StreamWriter(fs);

            try
            {
                Encrypt ept = new Encrypt(EncryptKey, false);

                context = ept.EncryptStr(context);

                sw.Write(context);
                sw.Flush();
            }
            finally
            {
                sw.Close();
                fs.Close();
            }
        }