不知道这是phpcms系统的错误还是php的错误，还是我自身的错误

<?php
defined(‘IN_PHPCMS‘) or exit(‘No permission resources.‘);
pc_base::load_app_func(‘global‘);
	class index{
		private $db;
		private $content_db;
		private $order_db;
		public function __construct(){
			
		}
		/**
		 * 处理，填写订单信息
		 */
		public function init(){
			new_addslashes(new_html_special_chars($_POST));
			extract($_POST[‘info‘]);
			$this->content_db=pc_base::load_model(‘content_model‘);
			$this->content_db->set_model($modelid);
			$line_data=$this->content_db->get_content($catid,$line_id);
			//print_r($line_data);
			$prices=string2array($line_data[‘price‘]);
			if ($is_group == 1){
				foreach ($prices as $key =>$val){
					if ($val[‘title‘] == $line_type){
						$price_group=$prices[$key];
					}
				}
				unset($prices);
				$prices[0]=$price_group;
			}
			$order_sn=get_order_sn();
			include	template(‘order‘,‘index‘);		
		}
		/**
		 * 处理，确认订单信息
		 */
		public function confirm_order(){
			new_addslashes(new_html_special_chars($_POST));
			extract($_POST[‘info‘]);
			include	template(‘order‘,‘confirm_order‘);
		}
		/**
		 * 保存订单
		 */
		public function save_order(){
			new_addslashes(new_html_special_chars($_POST));
			$this->order_db = pc_base::load_model(‘order_model‘);   //加载模型并且实例化
			$this->db = pc_base::load_model(‘order_model‘);   //加载模型并且实例化
			ReflectionObject::export($this->order_db);   //反射输出的是一样的
			ReflectionObject::export($this->db);         //同上
			var_dump(method_exists($this->db, ‘add_order‘));  //true
			var_dump(is_callable(array($this->order_db, ‘add_order‘)));  //true     
			var_dump(method_exists($this->order_db, ‘add_order‘));     //true
			var_dump(is_callable(array($this->db, ‘add_order‘)));    //true
			$this->db->add_order();     //可以调用
			$this->order_db—>add_order();   //不可以调用，致命错误  Fatal error: Call to undefined function add_order() in /var/www/html/line/phpcms/modules/order/index.php on line 56
			include template(‘order‘,‘save_order‘);
		}
	}