模型上的codeigniter未定义属性错误

我的模型出现未定义属性错误。我使用火柴盒库进行模块化分离。我的MPProduct模型是：

class MProducts extends Model{
    /* function MProducts(){
        $this->load->module_model('cities','MCities');
     }*/

    public $home_city_id ='';

    function __construct(){
        parent::Model();
        $this->home_city_id = $this->MCities->getHomeCityId();
    }
}

我得到了这个错误：

A PHP Error was encountered

Severity: Notice

Message: Undefined property: MProducts::$MCities

Filename: models/mproducts.php

Line Number: 12

我的模型是：

class MCities extends Model{

    function MCities(){
        parent::Model();
    }
function getHomeCityId(){
        $city = get_cookie('home_city');
         $this->db->select('id');
         $this->db->where('name', $city);
         $Q = $this->db->get('omc_cities');
         if($Q->num_rows() > 0){
             foreach ($Q->result_array() as $row){
             return $row['id'];
           }
        }
    }

}

我不知道这两种方法都不对

已编辑 我的产品控制器是这样的：

class Admin extends Shop_Admin_Controller {
    function Admin(){
        parent::Shop_Admin_Controller();
        // Check for access permission
        check('Products');
        // load modules/categories/model/mcats
         $this->load->module_model('categories','MCats');
        // load the MProducts model
        $this->load->model('MProducts');
        // load modules/cities/model/mcities
        $this->load->module_model('cities','MCities');
        // Set breadcrumb
        $this->bep_site->set_crumb($this->lang->line('backendpro_products'),'products/admin');       
    }


    function index(){
        // Setting variables
        $data['title'] = "Manage Products";
        $data['products'] = $this->MProducts->getAllProducts();
        $data['cities'] = $this->MCities->getCitiesDropDown();
        $data['categories'] = $this->MCats->getCategoriesDropDown();
        // we are pulling a header word from language file
        $data['header'] = $this->lang->line('backendpro_access_control');
        $data['page'] = $this->config->item('backendpro_template_admin') . "admin_product_home";
        $data['module'] = 'products';
        $this->load->view($this->_container,$data);
    }
}

class MProducts extends Model{
    /* function MProducts(){
        $this->load->module_model('cities','MCities');
     }*/

    public $home_city_id ='';

    function __construct(){
        parent::Model();
        $CI =& get_instance();

        $this->home_city_id = $CI->MCities->getHomeCityId()->getHomeCityId();
    }
}

---

在MPProducts的构造函数中，您可以这样做：

$this->MCities->getHomeCityId（）

这意味着您尝试获取mpProducts对象的MCities变量，然后调用

getHomeCityId（）什么将不起作用，因为查看您的MPProducts没有
MCities
var

编辑：
您必须在模型中获得codeigniter实例，并从CI实例检索MCities模型

MPProducts应该是这样的：

class Admin extends Shop_Admin_Controller {
    function Admin(){
        parent::Shop_Admin_Controller();
        // Check for access permission
        check('Products');
        // load modules/categories/model/mcats
         $this->load->module_model('categories','MCats');
        // load the MProducts model
        $this->load->model('MProducts');
        // load modules/cities/model/mcities
        $this->load->module_model('cities','MCities');
        // Set breadcrumb
        $this->bep_site->set_crumb($this->lang->line('backendpro_products'),'products/admin');       
    }


    function index(){
        // Setting variables
        $data['title'] = "Manage Products";
        $data['products'] = $this->MProducts->getAllProducts();
        $data['cities'] = $this->MCities->getCitiesDropDown();
        $data['categories'] = $this->MCats->getCategoriesDropDown();
        // we are pulling a header word from language file
        $data['header'] = $this->lang->line('backendpro_access_control');
        $data['page'] = $this->config->item('backendpro_template_admin') . "admin_product_home";
        $data['module'] = 'products';
        $this->load->view($this->_container,$data);
    }
}

class MProducts extends Model{
    /* function MProducts(){
        $this->load->module_model('cities','MCities');
     }*/

    public $home_city_id ='';

    function __construct(){
        parent::Model();
        $CI =& get_instance();

        $this->home_city_id = $CI->MCities->getHomeCityId()->getHomeCityId();
    }
}

我希望这有帮助。
您试图访问模型内部的MCITES，但模型与控制器是分离的。这就是为什么你必须在控制器中，而不是在模型中，我不知道在控制器中放在哪里。请你详细地告诉我或者举个例子。事实上我不知道你的控制器是什么样子。啊，好的，现在我明白问题了。我改变了答案。这应该行得通。