这种写法的级联 难道就真不行吗 ?

[Ooooonly]

数据库三张表
A省 B市 C区

A里面字段
id
pid
pname

B里面字段
id
cid
pid
cname

C里面字段
id
aid
aname
cid

 
省份
         public static string aaa()
        {
            DataTable dt = new DataTable();
            dt = TruckRules.TruckChinaProvinceRules.SelectChinaProvinceList();
            StringBuilder st = new StringBuilder();
            string F_ProvinceId = "";
            st.Append("<option value=\"\">--请选择--</option>");
            st.Append("<option value=\"\">全国</option>");
            foreach (DataRow dr in dt.Rows)
            {
                st.Append("<option value=\"" + pid+ "\">" + dr["pname"] + "</option>");

            }
            return st.ToString();
        }
城市
        public static string sss(string pid) 
        {
            DataTable dt = new DataTable();
            dt = TruckRules.TruckChinaProvinceRules.SelectProvinceByCityPidFill(pid);
            StringBuilder st = new StringBuilder();
            st.Append("<option value=\"\">--请选择--</option>");
            foreach (DataRow dr in dt.Rows)
            {
                st.Append("<option value=\"" + dr["cid"] + "\">" + dr["cname"] + "</option>");

            }
          return st.ToString();
        }
区县
        public static string rrr(string cid)
        {
            DataTable dt = new DataTable();
            dt = TruckRules.TruckChinaProvinceRules.GetCityByAreasFill(cid);
            StringBuilder st = new StringBuilder();
            st.Append("<option value=\"\">--请选择--</option>");
            foreach (DataRow dr in dt.Rows)
            {
                st.Append("<option value=\"" + dr["aid"] + "\">" + dr["aname"] + "</option>");

            }
            return st.ToString();
        }

           a.aspx.cs后台
            aa = TruckFunction.TruckChinaCityFunction.aaa();
            ss = TruckFunction.TruckChinaCityFunction.sss(pid);
            rr = TruckFunction.TruckChinaCityFunction.rrr(cid);

                            <select id="selectP"><%=aa %></select>省
                            <select id="selectC"><%=ss %></select>市
                            <select id="selectA"><%=rr %></select>区/县

现在只能取到省份, 为什么点击省份不显示城市 我id传的不对还是写法不对啊 求指教 !

[昵称不能为空噢噢噢噢]

看不出来