在.Net MVC

如何解决在.Net MVC

我有一个生成工作单列表的函数：

 public async Task<Object> GetAllWorkOrdersForUserAsync(string from,string to,int start,int length)
        {

                IQueryable<ReportWorkOrderViewModel> resp;
          
                resp = (from wo in _dbContext.WorkOrders
                        join woc in _dbContext.WorkOrderCategory on wo.WorkOrderCategoryId equals woc.Id
                        join sc in _dbContext.ServiceClients on wo.ServiceClientId equals sc.Id
                        join usr in _dbContext.Users on wo.UserId equals usr.Id into user
                        from uur in user.DefaultIfEmpty()
                        join contractor in _dbContext.Users on wo.ContractorId equals contractor.Id into contr
                        from contor in contr.DefaultIfEmpty()
                        select new ReportWorkOrderViewModel
                        {
                            Id = wo.Id,WorkOrderType = woc.Name,CustomerName = sc.FirstName + " " + sc.LastName,CustomerAccount = wo.ServiceClientId,AppointmentDate = wo.StartDateTime.ToString(),IsHiring = (userId == wo.UserId),CreatedAtDate = wo.CreatedAt.ToString(),CreatedAtTime = wo.CreatedAt.ToString(),CreatedBy = uur != null ? (uur.CompanyName != string.Empty ? uur.CompanyName : uur.ContactFirst + " " + uur.ContactLast) : string.Empty,AssignedTechnician = contor != null ? (contor.ContactFirst + " " + contor.ContactLast) : string.Empty,AppointmentTime = wo.StartDateTime.ToString(),City = sc.City,State = sc.State,TicketStatus = wo.Status,CompletionNote = wo.WorkPerformedDetail,ClientsNote = wo.CustomerNotes,TechStatus = wo.TechStatus == TechnicianStatus.Arrived ? "Arrivied" : wo.TechStatus == TechnicianStatus.OnTheWay ? "On The Way" : "Init",});


            int totalRows = resp.Count();

            
            if (!string.IsNullOrEmpty(from) && !string.IsNullOrEmpty(to))
            {
                try
                {
                    DateTime fromDate = DateTime.Parse(from);
                    DateTime toDate = DateTime.Parse(to);

                   resp = resp.AsEnumerable().Where(d => Convert.ToDateTime(d.AppointmentDate) >= fromDate && Convert.ToDateTime(d.AppointmentDate) <= toDate).AsQueryable();
                }
                catch
                {
                }
            }


            int totalRowsAfterFiltering = resp.Count();
            //<!--sorting-->
            resp = resp.OrderBy(searchColumnName + " " + sortDirection);
            
           
            //<!--paging-->
            if (paginate)
            {
                if (totalRowsAfterFiltering != totalRows)
                {
                    resp = resp.Skip(start).Take(length);
                }
                else
                {
                    resp = resp.Where(x => x.Id >= start).Take(length);
                }
            }
            var response = new
            {
                data = resp,recordsTotal = totalRows,recordsFiltered = totalRowsAfterFiltering
            };

            return response;
        }

我的ViewModel是

 public class ReportWorkOrderViewModel
    {
        public int Id { get; set; }
        public string WorkOrderType { get; set; }
        public int CustomerAccount { get; set; }
        public string CustomerName { get; set; }

        private string appointmentDate;
        public string AppointmentDate { get => appointmentDate; set => appointmentDate = Convert.ToDateTime(value).ToString("MM/dd/yyyy"); }
        private string appointmentTime;
        public string AppointmentTime { get => appointmentTime; set => appointmentTime = Convert.ToDateTime(value).ToString("HH:mm tt"); }
        public string CreatedBy { get; set; }
}

当From和To没有值时，上面的函数可以正常工作并生成所有列表。列表中的总数为6-7000，但是当我需要通过日期和时间进行数据过滤的列表时。我的系统在这部分代码中停留在int totalRowsAfterFiltering = resp.Count();中15到20秒，最后仅填充了2/3数据。但是，当我不按日期筛选时，列表将在2秒内执行。这是什么问题？