使用linq排序，想改进下，求指教

        /// <summary>
        /// 对数据源进行排序
        /// </summary>
        /// <param name="pStudentInfoList">需要排序的数据源</param>
        /// <param name="pSortExpression">排序字段</param>
        /// <param name="pSortDeriction">排序的方向</param>
        /// <returns>StudentInfo类型的list</returns>
        public static List<StudentInfo> GetListSorted(List<StudentInfo> pStudentInfoList, SortKeys pSortExpression, SortDeriction pSortDeriction)
        {
            List<StudentInfo> ds = new List<StudentInfo>();
            if (pSortDeriction == SortDeriction.DESC)
            {
                switch (pSortExpression)
                {
                    case SortKeys.StudentId:
                        ds = pStudentInfoList.OrderByDescending(studentinfo => studentinfo.StudentId).ToList<StudentInfo>();
                        break;
                    case SortKeys.StudentName:
                        ds = pStudentInfoList.OrderByDescending(studentinfo => studentinfo.StudentName).ToList();
                        break;
                    case SortKeys.Birthday:
                        ds = pStudentInfoList.OrderByDescending(studentinfo => studentinfo.Birthday).ToList();
                        break;
                    case SortKeys.Sex:
                        ds = pStudentInfoList.OrderByDescending(studentinfo => studentinfo.Sex).ToList();
                        break;
                }
            }