利用反射调用用户控件方法

       /*加入试卷规则 - 利用反射调用控件的提交方法*/
                UserControl uc = (UserControl)PlaceHolderRule.Controls[0];
                Type userType = uc.GetType();
                MethodInfo m = userType.GetMethod("submit");
                object[] objParas = new object[1];
                objParas[0] = examPaperID;
                m.Invoke(uc, objParas);