ef unitofwork 主从表更新

   readonly UnitOfWork _u = new UnitOfWork();

        public M Get(int id) {
            return _u.T_MtnContractRepository().SingleOrDefault(t => t.ID == id);
        }

        /// <summary>
        /// 编辑对应的合同与记录
        /// </summary>
        /// <param name="m"></param>
        public void Edit(M m) {
            var dbm = _u.T_MtnContractRepository().GetById(m.ID);
            var oldIds = dbm.T_MtnContractDetail.Select(a => a.ID).ToList();
            var newIds = m.T_MtnContractDetail.Select(a => a.ID).ToList();
            oldIds.ForEach(a => {
                if (newIds.Contains(a))
                    _u.T_MtnContractDetailRepository().Update(m.T_MtnContractDetail.First(b => b.ID == a));
                else {
                    _u.T_MtnContractDetailRepository().Delete(a);
                }
            });
            m.T_MtnContractDetail.ForEach(a => {
                a.T_MtnContract_ID = m.ID;
                if (!oldIds.Contains(a.ID)) _u.T_MtnContractDetailRepository().Insert(a);
            });
            _u.T_MtnContractRepository().Update(m);
            _u.Save();
        }