控制器无法呈现正确的模板

Question

我有一个带有动作上传和地图的控制器。如果用户成功上传文件，我会重定向用户 到地图行动。在此操作中，用户可以将文件映射到实体列。我的问题是“MapAction” 仅按字面意思呈现为响应

class ImportController
{

    public function uploadAction(Request $request) 
    {
        /** @TODO something **/
        $fileName = 'test';
        $params = ['fileName' => $fileName];
        $form = $this->createForm(new UploadType());
        if ($form->isValid() 
        {
            return $this->redirect($this->generateUrl('import_map', $params));
        }
return $this->render('AcmeAppBundle:Import:upload.html.twig', ['form' => $form->createView()]);
    }

    public function mapAction(Request $request, $fileName)
    {
        /** @TODO something **/
        $form = $this->createForm(new MappingType());

        // die("I reach this point successful"); 
        // Render result
        return $this->render('AcmeAppBundle:Import:mapping.html.twig', ['form' => $form->createView()]);
    }

}

这是我的控制器：

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

{% block content %}
    {{ form_start(form, {'attr': {'novalidate': 'novalidate'}})  }}
        {{ form_widget(form) }}
        <button type="submit" class="btn btn-primary">{% trans %}upload{% endtrans %}</button>
    {{ form_end(form) }}
{% endblock %}

这是我的Twig模板：

import_map:
    path:     /import-map/{fileName}
    defaults: { _controller: AcmeAppBundle:Import:map}

以下是我对import_map的路由：

public function actionCreate()
{
    $model = new Employeeinformation();

    if ($model->load(Yii::$app->request->post())){

        $model->password = sha1($model->password);
        $model->created_date = date('Y-m-d H:i:s');
        if ($model->save())
            return $this->redirect(['view', 'id' => $model->employee_id]);
    } 
    return $this->render('create', [
        'model' => $model,
    ]);

}

为什么会出现此问题？有人可以给我一个暗示吗？