Twig致命错误

Question

我有一个大问题。我使用Twig模板，但现在我在屏幕上看到了错误页面。

Fatal error: Uncaught exception 'LogicException' with message 'You must set a loader first.' in C:\wampd\www\projects\weborangoo\vendor\twig\twig\lib\Twig\Environment.php on line 622（！）

LogicException: You must set a loader first. in C:\wampd\www\projects\weborangoo\vendor\twig\twig\lib\Twig\Environment.php on line 622

但我的装载机看起来像这样：

<?php

namespace Ilib\Template;

use Twig_Loader_Filesystem;
use Twig_Environment;

class Template extends Twig_Environment {

    public $template;
    public $loader;
    public $cache_dir = 'templates/cache';

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

    \Twig_Autoloader::register();

    $this->loader = new Twig_Loader_Filesystem( 'templates' );
    $this->twig   = new Twig_Environment( $this->loader ,  array ( 'cache'  =>  $this->cache_dir ));

    }

    public function display($name, array $context = array()) {
    parent::display($name, $context); }

   }

问题出在哪里？我需要在模板中显示数据，但数据是一个数组，所以我不知道错误在哪里。