如何解决这个问题，System.Linq.Dynamic.ParseException: No property or field asc exist in type 'TblEventsManagements'？

Question

在此处输入图像描述我有这个控制器 GetList 并且我正在使用 Linq.Dynamic 来过滤要搜索的表中的字段，这使用 dataTable 进行服务器端处理。 谁能帮我解决这个问题？ 以下是我抛出此错误的逻辑和行；

[\[HttpPost\]
   public ActionResult GetList()
    {
        //Server side Parameter.
        int start = Convert.ToInt32(Request\["start"\]);
        int length = Convert.ToInt32(Request\["length"\]);
        string searchValue = Request\["search\[value\]"\];
        string sortColumnName = Request\["columns\[" + Request\["order\[0\]\[column\]"\] + "\]\[name\]"\];
        string sortDirection = Request\["order\[0\]\[dir\]"\];


        using (eNtsaOnlineRegistrationDBContext db = new eNtsaOnlineRegistrationDBContext())
        {

            IQueryable<TblEventsManagements> empList = db.TblEventsManagements;
           int totalrows = empList.Count();
            int totalrowsafterfiltering = totalrows;


            if (!string.IsNullOrEmpty(searchValue))
            {
                empList = empList.Where(x => x.TrainingType.Contains(searchValue) || x.TrainingDescription.Contains(searchValue) || x.Price.ToString().Contains(searchValue.ToLower())
                || x.Venue.Contains(searchValue) || x.Facilitator.Contains(searchValue) || x.WhoAttend.Contains(searchValue) || x.Rsvp.Contains(searchValue));


            }


            empList = empList.OrderBy(sortColumnName + "" + sortDirection).Skip(start).Take(length);



            return Json(new { data = empList, draw = Request\["draw"\], recordsTotal = totalrows, recordsFiltered = totalrowsafterfiltering }, JsonRequestBehavior.AllowGet);
        }



    }][1]

我忘了打我的 Ajax 电话，我一开始以为问题是我的表中缺少字段。 现在我得到的字段或类型“TrainingTypeasc”不存在，它在我的数据库表上确实存在。 我在哪里可以改进这个逻辑伙伴？ 请帮忙。

 <script>

        $(document).ready(function () {

               $("#EventManagementTable").DataTable({
                "ajax": {
                    "url": "/Dashboard/GetList",
                    "type": "POST",
                    "datatype":"json"
                },
                   "columns": [
                    {"data": "TrainingType", "name": "TrainingType"},
                    { "data": "TrainingDescription", "name": "TrainingDescription" },
                    { "data": "Price", "name": "Price" },
                    { "data": "Venue", "name": "Venue" },
                    { "data": "Facilitator", "name": "Facilitator" },
                    { "data": "WhoAttend", "name": "WhoAttend" },
                    {"data": "RSVP", "name": "RSVP"},
                ],

                "serverSide": "true",
                "order":[0,"asc"],
                "processing": "true",
                "language": {
                    "processing":"processing... please wait"
                }



            });

        });

Answer 1

替换这个：

empList = empList.OrderBy(sortColumnName + "" + sortDirection).Skip(start).Take(length);

有了这个：

 empList = empList.OrderByPropertyName(sortColumnName,sortDirection).Skip(start).Take(length)

并将其添加到您的项目中：

using System.Collections.Generic;
using System.Linq;

namespace "YourNameSpace"
{
    public static class ListExtension
    {
        public static IOrderedEnumerable<T>  OrderByPropertyName<T>(this ICollection<T> list, string sortColumnName, string sortDirection)
        {
            var type = typeof(T);

            var property = sortColumnName == "" ? type.GetProperties().FirstOrDefault() : type.GetProperties().Where(p => p.Name == sortColumnName).FirstOrDefault();

            return sortColumnName == "asc" ? list.OrderBy(p => property.GetValue(p)) : list.OrderByDescending(p => property.GetValue(p));
        }

    }
}