List<Statbydate> rest = server.LineChart(bdate, edate);
            int max = 0, min = 0;
            if (rest.Count > 0)
            {
                max = rest[0].maxRegister; //最大值
                min = rest[0].minRegister; //最小值
            }
            
            IsoDateTimeConverter fmt = new IsoDateTimeConverter();  ///需要安装这个包
            fmt.DateTimeFormat = "yyyy-MM-dd";
            return Content(string.Format("{{\"max\":{0},\"min\":{1},\"data\":{2}}}", max, min, Newtonsoft.Json.JsonConvert.SerializeObject(rest,fmt)));
原文:https://www.cnblogs.com/yjm8023/p/9334135.html