/**
* 构造函数
*/
public function __construct()
{
//必须继承父类控制器
parent::__construct();
//实例化模型
$this->model = Category_Model::instance();
$this->model->set_from($this->source, $this->appid, $this->device_id, $this->phone_model);
$this->_check_request();
}