List集合去掉重复数据

 BLL.BabyManager Baby_bll = new BLL.BabyManager();
        List<Model.Baby> Baby_List = new List<Model.Baby>();
        Baby_List = Baby_bll.Query_Baby(" * ","", " order by id desc");


        Baby_List.Distinct<Model.Baby>();
        Baby_List = Baby_List.GroupBy(t => t.typeid).Select(t => t.First()).ToList();