调度符号2中的错误

Question

我在研究Symfony的活动。我希望每次新用户注册时都发送一封电子邮件

我创建了这些类

UserEvent.php
    <?php
    namespace Acme\UserBundle\Event;


    final class UserEvents {

        const NEW_USER='new.user';


    } 

newUserEvent.php

<?php

/**
 * EVENT DISPATCHER
 */
namespace Acme\UserBundle\Event;

use Acme\UserBundle\Entity\User;
use Symfony\Component\EventDispatcher\Event;


class NewUserEvent {

    protected $user;

    public function __construct (User $user) {
        $this->user = $user;
    }

    public function getUser () {
        return $this->user;
    }
}

newUserListener.php

<?php

namespace Acme\UserBundle\Event;


class NewUserListener {

    public function sendEmailToUsers(NewUserEvent $event)
    {
        // ... send email to users
    }
} 

在我的控制器里

/**
     * @Route("/test",name="test")
     */
    public function testEvento(){

        $em = $this->getEm();

        $dispatcher = new EventDispatcher();

        // attach listener
        $listner = new NewUserListener();
        $dispatcher->addListener(UserEvents::NEW_USER,array($listner,'sendEmailToUsers'));

        $user = $em->getRepository('AcmeUserBundle:User')->findOneBy(array('username' => 'alex')); //mock
        $event = new NewUserEvent($user);

        $dispatcher->dispatch(UserEvents::NEW_USER,$event);



        return new Response('hi');
    }

但我知道这个错误

可捕获的致命错误:传递给Symfony\Component\EventDispatcher\EventDispatcher::dispatch()的参数2必须是Symfony\Component\EventDispatcher\EventDispatcher\ContextErrorException的实例

我不明白我的错误

Answer 1

看看这个。

1. class NewUserEvent必须扩展Event类(Symfony\Component\EventDispatcher\Event)
2. 在控制器中访问event_dispatcher服务- $this->get('event_dispatcher')