/// <summary>
        /// 构造器
        /// </summary>
        /// <param name="source"></param>
        /// <param name="SlaveId"></param>
        public MongoContext(MongoPointEnum source, int SlaveId, string dbName, string objName)
        {
            this.Source  = source;
            this.SlaveId = SlaveId;
            var db = MongoBuilder.Instance.GetConnection(Source, SlaveId).GetDatabase(dbName);

            collection = db.GetCollection <T>(objName);
        }
 /// <summary>
 /// 获得数据库连接
 /// </summary>
 /// <returns></returns>
 public MongoClient GetConnection(MongoPointEnum sourcePointEnum, int slaveId)
 {
     try
     {
         if (sourcePointEnum == MongoPointEnum.Master)
         {
             //主库
             return(new MongoClient(ConfigHelper.MongoMasterConnectionString));
         }
         else
         {
             //从库
             return(new MongoClient(ConfigHelper.MongoSlaveConnectionString[slaveId > 0 ? slaveId - 1 : 0]));
         }
     }
     catch
     {
         throw;
     }
 }