Php Ajax下拉列表，用于国家和地区；代码点火器中的城市？

在我们的codeigniter框架中，我借助ajax使country state和city下拉列表

下面给出了数据库的结构

国家

country_id,country_name

country_id,state_id,city_id,city_name

状态

country_id,state_id,state_name

 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;
        }
    }

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;
      }
}

城市

country_id,country_name

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

<?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 />

城市模型模块

country_id,state_id,state_name

 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;
        }
    }

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>

---

/创建一个javascript变量

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

使用firefox和firebug调试ajax代码
正如我在评论中所说，您可以使用或（网络选项卡）来确定您的问题：

控制器：

<?php
class ctrl extends ci_controller{
    function index(){ //I just used this one to test out if its outputing anything
        $names = ['apple','ball','cat','dog'];
        echo json_encode($names);
    }

    function load_view(){ 
        $this->load->view('ctrl_view');
    }
}
?>



视图：


$.post（'ctrl/'，函数（数据）{//您可以在此处调用控制器
var parsed_data=JSON.parse（数据）；
//使用文档片段将新元素附加到dom中，而不是在dom中现有元素的循环的每次迭代中都附加新元素，这是一种很好的做法
var fragment=document.createDocumentFragment（）；
for（解析的_数据中的变量x）{
var val=已解析的_数据[x]；
var选项=$（“”）.val（val）.text（val）；
fragment.appendChild（选项[0]）；
}
$（'#names'）.append（fragment）；//将整个片段附加到循环之外
});

我真的不知道你的实际问题是什么，所以请帮个忙，编辑你的问题并粘贴你在firebug上看到的错误

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)));
}

在这个函数中，您输入了不正确的变量名，$dealCountry
到底是什么不起作用？ajax调用没有返回任何内容吗？您是否使用firebug或chrome开发工具来识别您的问题？ajax不会返回任何东西！帮个忙，把你在firebug上看到的错误贴出来。您的问题很可能是路径中的问题。您可能希望首先将基本url分配给config.php文件中的空字符串。