public object Getmonitorhistory(string id)
        {
            try
            {
                var ret = from n in Monitorcurrent.Query(t => t.Mac == id).Result
                          group n by n.Monitor_Time
                          into s
                          select new
                {
                    Ip_Address    = s.Select(t => t.Ip_Address).Take(1),
                    Mac           = s.Select(p => p.Mac).Take(1),
                    Monitor_Name  = s.Select(t => t.Monitor_Name),
                    Monitor_Value = s.Select(t => t.Monitor_Value),
                    Monitor_Time  = s.Select(t => t.Monitor_Time).Take(1)
                };
                Console.WriteLine(ret.ToJson());


                return(ret.ToJson());
            }
            catch (Exception)
            {
                return("数据错误");
            }
        }
 public object Getmonitorcurrent(int page, int limit)
 {
     try
     {
         var lsq = from n in Monitorcurrent.Query().Result
                   group n by n.Mac
                   into s
                   select new {
             Ip_Address    = s.Select(p => p.Ip_Address).Take(1),
             Mac           = s.Select(p => p.Mac).Take(1),
             Monitor_Name  = s.Select(p => p.Monitor_Name),
             Monitor_Value = s.Select(p => p.Monitor_Value),
             Monitor_Time  = s.Select(p => p.Monitor_Time).Take(1)
         };
         var ret = new{ code = 0, msg = "", data = lsq, count = lsq.Count() };
         return(ret.ToJson());
     }
     catch (Exception)
     {
         return("数据错误");
     }
 }