/// <summary>
        ///     获取实例节点
        /// </summary>
        /// <param name="mongoConnKey"></param>
        /// <param name="config">由于是结构体,必须ref</param>
        /// <param name="mongoConn"></param>
        /// <param name="mMasterServerInstace"></param>
        /// <param name="mServer"></param>
        /// <param name="UserList"></param>
        /// <returns></returns>
        private static TreeNode GetInstanceNode(String mongoConnKey,
                                                ref ConfigHelper.MongoConnectionConfig config,
                                                MongoServer mongoConn,
                                                MongoServerInstance mMasterServerInstace,
                                                MongoServer mServer,
                                                EachDatabaseUser UserList)
        {
            bool isReplsetMasterServer = mMasterServerInstace == null;
            //无论如何,都改为主要服务器读优先
            var    svrInstanceNode = new TreeNode();
            String connSvrKey;

            connSvrKey = isReplsetMasterServer
                ? mongoConnKey + "/" + mongoConnKey
                : mongoConnKey + "/" + mMasterServerInstace.Address.ToString().Replace(":", "@");
            svrInstanceNode.SelectedImageIndex = (int)GetSystemIcon.MainTreeImageType.WebServer;
            svrInstanceNode.ImageIndex         = (int)GetSystemIcon.MainTreeImageType.WebServer;
            svrInstanceNode.Text = isReplsetMasterServer ? "Connection" : "Server[" + mMasterServerInstace.Address + "]";
            if (!String.IsNullOrEmpty(config.UserName) & (!String.IsNullOrEmpty(config.Password)))
            {
                //是否是认证模式,应该取决于服务器!
                config.AuthMode = true;
            }
            //获取ReadOnly
            config.IsReadOnly = false;
            List <string> databaseNameList;

            if (!String.IsNullOrEmpty(config.DataBaseName))
            {
                //单数据库模式
                TreeNode mongoSingleDbNode;
                mongoSingleDbNode = isReplsetMasterServer
                    ? FillDataBaseInfoToTreeNode(config.DataBaseName, mServer,
                                                 mongoConnKey + "/" + mongoConnKey)
                    : FillDataBaseInfoToTreeNode(config.DataBaseName, mServer,
                                                 mongoConnKey + "/" + mMasterServerInstace.Address);
                mongoSingleDbNode.Tag = MongoDbHelper.SINGLE_DATABASE_TAG + ":" + connSvrKey + "/" + config.DataBaseName;
                mongoSingleDbNode.SelectedImageIndex = (int)GetSystemIcon.MainTreeImageType.Database;
                mongoSingleDbNode.ImageIndex         = (int)GetSystemIcon.MainTreeImageType.Database;
                svrInstanceNode.Nodes.Add(mongoSingleDbNode);
                svrInstanceNode.Tag = MongoDbHelper.SINGLE_DB_SERVER_TAG + ":" + connSvrKey;
                //获取User信息
                if (config.AuthMode)
                {
                    try
                    {
                        //尝试添加用户信息
                        UserList.AddUser(mongoConn.GetDatabase(config.DataBaseName), config.UserName);
                    }
                    catch
                    {
                        //可能出现没有权限的问题,这里就认为无法取得权限
                    }
                }
            }
            else
            {
                MongoServer instantSrv;
                if (isReplsetMasterServer)
                {
                    instantSrv       = mServer;
                    databaseNameList = mServer.GetDatabaseNames().ToList();
                }
                else
                {
                    MongoClientSettings setting = MongoDbHelper.CreateMongoClientSettingsByConfig(ref config);
                    setting.ConnectionMode = ConnectionMode.Direct;
                    //When Replset Case,Application need to read admin DB information
                    //if Primary,there will be exception
                    setting.ReadPreference = ReadPreference.PrimaryPreferred;
                    setting.Server         = mMasterServerInstace.Address;
                    instantSrv             = new MongoClient(setting).GetServer();
                    databaseNameList       = instantSrv.GetDatabaseNames().ToList();
                }
                foreach (String strDbName in databaseNameList)
                {
                    TreeNode mongoDbNode;
                    try
                    {
                        mongoDbNode                    = FillDataBaseInfoToTreeNode(strDbName, instantSrv, connSvrKey);
                        mongoDbNode.ImageIndex         = (int)GetSystemIcon.MainTreeImageType.Database;
                        mongoDbNode.SelectedImageIndex = (int)GetSystemIcon.MainTreeImageType.Database;
                        svrInstanceNode.Nodes.Add(mongoDbNode);
                        if (config.AuthMode)
                        {
                            try
                            {
                                //尝试添加用户信息
                                UserList.AddUser(mongoConn.GetDatabase(strDbName), config.UserName);
                            }
                            catch
                            {
                                //可能出现没有权限的问题,这里就认为无法取得权限
                            }
                        }
                    }
                    catch (Exception ex)
                    {
                        SystemManager.ExceptionDeal(ex, strDbName + "Exception", strDbName + "Exception");
                        mongoDbNode = new TreeNode(strDbName + " (Exception)")
                        {
                            ImageIndex         = (int)GetSystemIcon.MainTreeImageType.Database,
                            SelectedImageIndex = (int)GetSystemIcon.MainTreeImageType.Database
                        };
                        svrInstanceNode.Nodes.Add(mongoDbNode);
                    }
                }
                if (isReplsetMasterServer)
                {
                    svrInstanceNode.Tag = MongoDbHelper.SERVER_TAG + ":" + mongoConnKey + "/" + mongoConnKey;
                }
                else
                {
                    if (mongoConn.ReplicaSetName != null)
                    {
                        svrInstanceNode.Tag = MongoDbHelper.SERVER_REPLSET_MEMBER_TAG + ":" + mongoConnKey + "/" +
                                              mMasterServerInstace.Address.ToString().Replace(":", "@");
                    }
                }
            }
            if (MongoDbHelper._mongoInstanceLst.ContainsKey(connSvrKey))
            {
                MongoDbHelper._mongoInstanceLst.Remove(connSvrKey);
            }
            if (!isReplsetMasterServer)
            {
                MongoDbHelper._mongoInstanceLst.Add(connSvrKey, mMasterServerInstace);
            }
            return(svrInstanceNode);
        }