C# EF中调用 存储过程并调回参数

            TourEntities db = new TourEntities();
            List<v_product> v = new List<v_product>();

            SqlParameter[] prams = new SqlParameter[5];
            prams[0] = new SqlParameter("@a", 0);
            prams[1] = new SqlParameter("@b", 0);
            prams[1].Direction = ParameterDirection.Output;
            prams[2] = new SqlParameter("@c", 0);
            prams[3] = new SqlParameter("@d", 0);
            prams[4] = new SqlParameter("@e", 0);

            try
            {
                v = db.Database.SqlQuery<v_product>("exec dbo.proc_list @a,@b out,@c,@d,@e", prams).ToList();
                pageCount = ConvertHelp.ObjToInt(prams[1].Value, 0);
            }
            catch (Exception) { }