为什么在树枝Symfony中不存在变量？

Question

我想打印所有类别在我嫩枝这样：

<div class="col-md-3"> 
       <p class="lead">Categories</p> 
       <div class="list-group"> 
        {% for category in categories %} 
        <a href="#" class="list-group-item">{{ category.name }}</a> 
        {% endfor %} 
       </div> 
</div> 

但它告诉我，变量类别不存在。

枝杈结构：

{% extends 'base.html.twig' %} 

{% block body %} 
    <!-- Page Content --> 
    <div class="container"> 

     <div class="row"> 

      <div class="col-md-3"> 
       <p class="lead">Categories</p> 
       <div class="list-group"> 
        {% for category in categories %} 
         <a href="#" class="list-group-item">{{ render(controller(
           'AppBundle:Category:listCategories' 
          )) }}</a> 
        {% endfor %} 
       </div> 
      </div> 

      <div class="col-md-9"> 

       <div class="row carousel-holder"> 

        <div class="col-md-12"> 
         <div id="carousel-example-generic" class="carousel slide" data-ride="carousel"> 
          <ol class="carousel-indicators"> 
           <li data-target="#carousel-example-generic" data-slide-to="0" class="active"></li> 
           <li data-target="#carousel-example-generic" data-slide-to="1"></li> 
           <li data-target="#carousel-example-generic" data-slide-to="2"></li> 
          </ol> 
          <div class="carousel-inner"> 
           <div class="item active"> 
            <img class="slide-image" src="https://files.illinoispolicy.org/wp-content/uploads/2016/09/Garbage-Politicians-Jesse-White-800x300.png" alt=""> 
           </div> 
           <div class="item"> 
            <img class="slide-image" src="https://files.illinoispolicy.org/wp-content/uploads/2016/07/garbage-politicians-michael-madigan-800x300.png" alt=""> 
           </div> 
           <div class="item"> 
            <img class="slide-image" src="https://files.illinoispolicy.org/wp-content/uploads/2015/03/lion-meat-act-2-800x300.jpg" alt=""> 
           </div> 
          </div> 
          <a class="left carousel-control" href="#carousel-example-generic" data-slide="prev"> 
           <span class="glyphicon glyphicon-chevron-left"></span> 
          </a> 
          <a class="right carousel-control" href="#carousel-example-generic" data-slide="next"> 
           <span class="glyphicon glyphicon-chevron-right"></span> 
          </a> 
         </div> 
         <br> 
        </div> 

       </div> 

       <div class="row"> 

        <div class="col-sm-4 col-lg-4 col-md-4"> 
         <div class="thumbnail"> 
          <img src="http://placehold.it/320x150" alt=""> 
          <div class="caption"> 
           <h4 class="pull-right">$24.99</h4> 
           <h4><a href="#">First Product</a> 
           </h4> 
           <p>See more snippets like this online store item at <a target="_blank" href="http://www.bootsnipp.com">Bootsnipp - http://bootsnipp.com</a>.</p> 
          </div> 
          <div class="ratings"> 
           <p class="pull-right">15 reviews</p> 
           <p> 
            <span class="glyphicon glyphicon-star"></span> 
            <span class="glyphicon glyphicon-star"></span> 
            <span class="glyphicon glyphicon-star"></span> 
            <span class="glyphicon glyphicon-star"></span> 
            <span class="glyphicon glyphicon-star"></span> 
           </p> 
          </div> 
         </div> 
        </div> 

        <div class="col-sm-4 col-lg-4 col-md-4"> 
         <div class="thumbnail"> 
          <img src="http://placehold.it/320x150" alt=""> 
          <div class="caption"> 
           <h4 class="pull-right">$64.99</h4> 
           <h4><a href="#">Second Product</a> 
           </h4> 
           <p>This is a short description. Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p> 
          </div> 
          <div class="ratings"> 
           <p class="pull-right">12 reviews</p> 
           <p> 
            <span class="glyphicon glyphicon-star"></span> 
            <span class="glyphicon glyphicon-star"></span> 
            <span class="glyphicon glyphicon-star"></span> 
            <span class="glyphicon glyphicon-star"></span> 
            <span class="glyphicon glyphicon-star-empty"></span> 
           </p> 
          </div> 
         </div> 
        </div> 

        <div class="col-sm-4 col-lg-4 col-md-4"> 
         <div class="thumbnail"> 
          <img src="http://placehold.it/320x150" alt=""> 
          <div class="caption"> 
           <h4 class="pull-right">$74.99</h4> 
           <h4><a href="#">Third Product</a> 
           </h4> 
           <p>This is a short description. Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p> 
          </div> 
          <div class="ratings"> 
           <p class="pull-right">31 reviews</p> 
           <p> 
            <span class="glyphicon glyphicon-star"></span> 
            <span class="glyphicon glyphicon-star"></span> 
            <span class="glyphicon glyphicon-star"></span> 
            <span class="glyphicon glyphicon-star"></span> 
            <span class="glyphicon glyphicon-star-empty"></span> 
           </p> 
          </div> 
         </div> 
        </div> 
       </div> 

      </div> 

     </div> 

    </div> 
{% endblock %} 

如y尝试在其他的模板，它的工作要做，但我想这样做的网页树枝

这里是我的控制器：

public function listCategoriesAction() 
    { 
     $em = $this->getDoctrine()->getManager(); 
     $categoryRepository = $em->getRepository('AppBundle:Category'); 
     $categories = $categoryRepository->findAll(); 

     return $this->render('homepage/homepage.html.twig', array(
      'categories' => $categories->getResult() 
     )); 
    } 

Answer 1

如果您想在此变体中呈现内容：

<pre><code> 
{% for category in categories %} 
{{ category.name }} 
{% endfor %} 
</code></pre> 

您必须生成器这个数据并返回响应：在我的测试progect

    $em = $this->getDoctrine()->getManager(); 
    $categoryRepository = $em->getRepository('YouBundle:Category'); 
    $category = $categoryRepository->findAll(); 

    return $this->render(
    'MainBundle:Admin/page:order.html.twig', 
     [ 
     'categories' => $category->getResult(), 
     ]); 

听链接：
控制器 - TIK
模板 - TIK

希望它的桅杆帮助。