https://blog.csdn.net/wumiju/article/details/80429412

 public partial class ProductTypeModel:DbEntityModels.ProductType

    {

        public List<ProductTypeModel> SubProductTypeInfo { get; set; }

        

    }

  public IActionResult ListProductType()

        {

            List<Models.ProductTypeModel> listType = new List<Models.ProductTypeModel>();

          var  info = typeBll.Query(x => x.IsDelete == false && x.Fid == 0 && x.Depth == 0);

            foreach (var item in info)

            {

                listType.Add(new Models.ProductTypeModel()

                {

                    ID = item.ID,

                    IsDelete = item.IsDelete,

                    Depth = item.Depth,

                    CreateDate = item.CreateDate,

                    Fid = item.Fid,

                    Remark = item.Remark,

                    Sort = item.Sort,

                    TypeName = item.TypeName,

                    SubProductTypeInfo= subListProductType(item.ID)

                });

            }

            return Json(new { data = listType });

        }

        public List<Models.ProductTypeModel> subListProductType(long fid)

        {

            var dbProductTypeInfo = typeBll.Query(x => x.IsDelete == false && x.Fid == fid);

            List<Models.ProductTypeModel> listType = new List<Models.ProductTypeModel>();

            foreach (var item in dbProductTypeInfo)

            {

                listType.Add(new Models.ProductTypeModel()

                {

                    ID = item.ID,

                    IsDelete = item.IsDelete,

                    Depth = item.Depth,

                    CreateDate = item.CreateDate,

                    Fid = item.Fid,

                    Remark = item.Remark,

                    Sort = item.Sort,

                    TypeName = item.TypeName,

                    SubProductTypeInfo = subListProductType(item.ID)

                });

            }

            return listType;

        }