Ajax请求不能与Codeigniter一起使用

Question

我现在在互联网的帮助下自我练习Codeigniter。我现在能够创建几乎所有操作，但今天我尝试使用ajax调用来获取数据。什么都没有从数据库中检索，但在使用Chrome的调试器进行调试时，没有显示任何错误。我为这个问题打了六个小时。我尝试了一切，终于到了这里。

这是我的模型

public function member_id($postData)
      {
          $response = array();
           if($postData['member_id'] ){

   $this->db->select('*');
   $this->db->where('member_id', $postData['member_id']);
   $q = $this->db->get('tbl_test');
   $response = $q->result_array();

  }

  return $response;
      }

控制器

function __construct()
    {
        parent::__construct();

        $this->load->helper('url');
        $this->load->database();
        $this->_init();
    }
private function _init()
    {
        $this->output->set_template('default');
        $this->load->css('assets/themes/default/css/my.css');
        $this->load->css('assets/themes/default/css/bootstrap.css');
        $this->load->css('assets/themes/default/css/bootstrap-theme.css');


    }

public function index()
    {
        $data['title'] = "My Real Title";
        $this->load->view('pages/home',$data);
    }
public function feeDetails()
    {
       $postData  = $this->input->post();

       $this->load->model('Model');

       $data = $this->Model->member_id($postData);

           echo json_encode($data);
     }

查看

  <input class="form-control in2" id="txtmemid" placeholder="Member id " name="txtmemid" value="" style="text-transform:uppercase" type="text">
    <button type="submit" id="btnmemfeeview" class="btn btn-default ho showser fl ">Search</button>

   Bill No: <span id='bno'></span><br/>
   Bill date: <span id='bdate'></span><br/>
   Member id: <span id='mid'></span><br/>

最后这是我的 ajax

<script type='text/javascript'>
  $(document).ready(function(){

   $("#btnmemfeeview").click(function(){
    var member_id = $('#txtmemid').val();
    $.ajax({
     url:'<?=base_url()?>index.php/Pages/feeDetails',
     method: 'post',
    data: {member_id: member_id},
     dataType: 'json',
     success: function(response){
      var len = response.length;

      if(len > 0){
       // Read values

       var bno = response.BILL_NO;
       var bdate = response.BILL_DATE;
       var mid = response.MEMBER_ID ;

       $('#bno').text(bno);
       $('#bdate').text(bdate);
       $('#mid').text(mid);

      }else{

       $('#bno').text('');
       $('#bdate').text('');
       $('#mid').text('');
      }

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