Symfony3控制器构造函数注入不起作用

我想使用以下代码将EntityManager实例传递给我的控制器的构造函数:

namespace AppBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Doctrine\ORM\EntityManager;

class UserController extends Controller
{

    public function __construct( EntityManager $entityManager )
    {
        // do some stuff with the entityManager
    }
}

我通过将参数放入service.yml文件来进行构造函数注入:

parameters:
#    parameter_name: value

services:
#    service_name:
#        class: AppBundle\Directory\ClassName
#        arguments: ["@another_service_name", "plain_value", "%parameter_name%"]
    app.user_controller:
        class: AppBundle\Controller\UserController
        arguments: ['@doctrine.orm.entity_manager']

service.yml包含在config.yml中,当我运行时

php bin/console debug:container app.user_controller

我明白了:

 Information for Service "app.user_controller"
 =============================================

 ------------------ ------------------------------------- 
  Option             Value                                
 ------------------ ------------------------------------- 
  Service ID         app.user_controller                  
  Class              AppBundle\Controller\UserController  
  Tags               -                                    
  Public             yes                                  
  Synthetic          no                                   
  Lazy               no                                   
  Shared             yes                                  
  Abstract           no                                   
  Autowired          no                                   
  Autowiring Types   -                                    
 ------------------ ------------------------------------- 

但是,调用映射到我的控制器的路由,我得到:

UserController.php第17行中的FatalThrowableError:类型错误:传递给AppBundle\Controller\UserController :: __ construct()的参数1必须是Doctrine\ORM\EntityManager的实例,没有给出,在/ home/michel/Documents/Terminfinder /中调用202号线上的vendor/symfony/symfony/src/Symfony/Component/HttpKernel/Controller/ControllerResolver.php

我无法弄清楚,为什么EntityManager没有被注入？