public JsonResult List([FromForm] string token)
        {
            DataResult dr = new DataResult();

            try
            {
                CourseRecommendBLL           courseRecommendBLL      = new CourseRecommendBLL();
                CourseBLL                    courseBLL               = new CourseBLL();
                CourseOrderBLL               courseOrderBLL          = new CourseOrderBLL();
                List <CourseRecommendEntity> courseRecommendEntities = courseRecommendBLL.ActionDal.ActionDBAccess.Queryable <CourseRecommendEntity>().ToList();

                courseRecommendEntities.ForEach(it =>
                {
                    List <int> vs = courseRecommendBLL.ActionDal.ActionDBAccess.Queryable <CourseRecommendCorrelationEntity>()
                                    .Where(itt => itt.courseRecommendId == it.courseRecommendId)
                                    .Select(itt => itt.courseId)
                                    .ToList();
                    if (vs.Count > 0)
                    {
                        it.courseEntities = courseBLL.ListByIdInts(vs);
                    }

                    if (it.courseEntities.Count > 0)
                    {
                        it.courseEntities.ForEach(i =>
                        {
                            i.countSold = courseOrderBLL.GetCountByCourseId(i.courseId);
                        });
                    }
                });

                dr.code = "200";
                dr.data = courseRecommendEntities;
            }
            catch (Exception ex)
            {
                dr.code = "999";
                dr.msg  = ex.Message;
            }

            return(Json(dr));
        }