DropDownList无刷新三级联动

DropDownList无刷新三级联动 caomianpublic void getDdlInfo(DropDownList province,DropDownList city,DropDownList town,Page myPage) { //初始化省 string sql="select 序号,省名 from 省表"; SqlCommand comm=new SqlCommand(sql,conn); province.Items.Clear(); province.Items.Add(new ListItem("-=请选择=-","0")); conn.O