Codeigniter 中国家/地区和城市的 Ajax 下拉菜单？

我正在我们的 Codeigniter 框架中借助 ajax 使国家和城市下降。

数据库的结构如下所示。

Country

country_id,country_name

State

country_id,state_id,state_name

city

country_id,state_id,city_id,city_name

用户控制器

function country(){
 $data['header']='Deal Management';
 $data['page'] = 'admin/page/user-view';
 $data['Country'] = $this->deal->getCountry(); 
 $this->load->view($this->_admin_container,$data);  
}

function get_cities($Country){
  $this->load->model('city_model');
  header('Content-Type: application/x-json; charset=utf-8');
  echo(json_encode($this->cities_model->get_cities($dealCountry)));
}

用户视图视图

<?php $cities['#'] = 'Please Select'; ?>

<label for="country">Country: </label><?php echo form_dropdown('country_id', $Country, '#', 'id="country"'); ?><br />

<label for="city">City: </label><?php echo form_dropdown('city_id', $cities, '#', 'id="cities"'); ?><br />

交易模块country_model

 function getCountry(){
    $this->db->select("*");
    $query=$this->db->get("deal_country");
    $countries = array();
    if($query->result()){
          foreach ($query->result() as $country) {
              $countries[$country->country_id] = $country->country_name;
          }
        return $countries;
        }else{
        return FALSE;
        }
    }

城市模型模块

function get_cities($dealCountry = null){
        echo $dealCountry;die;
      $this->db->select('city_id, city_name');

      if($dealCountry != NULL){
          $this->db->where('country_id', $dealCountry);
      }

      $query = $this->db->get('deal_city');

      $cities = array();

      if($query->result()){
          foreach ($query->result() as $city) {
              $cities[$city->id] = $city->city_name;
          }
      return $cities;
      }else{
          return FALSE;
      }
}

我在头文件中包含 ajax 脚本。

<script type="text/javascript">// <![CDATA[
    $(document).ready(function(){
        $('#country').change(function(){ //any select change on the dropdown with id country trigger this code
        $("#cities > option").remove(); //first of all clear select items
            var country_id = $('#country').val();  // here we are taking country id of the selected one.
            $.ajax({
                type: "POST",
                url: "home/get_cities/"+country_id, //here we are calling our user controller and get_cities method with the country_id

                success: function(cities) //we're calling the response json array 'cities'
                {
                    $.each(cities,function(city_id,city) //here we're doing a foeach loop round each city with id as the key and city as the value
                    {
                        var opt = $('<option />'); // here we're creating a new select option with for each city
                        opt.val(id);
                        opt.text(city);
                        $('#cities').append(opt); //here we will append these new select options to a dropdown with the id 'cities'
                    });
                }

            });

        });
    });
    // ]]>
</script>

编写代码后它不起作用。

任何帮助表示赞赏！

Thanks

创建一个 JavaScript 变量

var base_url = "<?=base_url()?>";

在你的 javascript 代码中 concat 它

url: base_url+"home/get_cities/"+country_id, 

使用 firefox 和 firebug 调试 ajax 代码