Yii2事件

namespace app\components;

use yii\base\Component;
use yii\base\Event;

class MessageEvent extends Event
{
public $message;
}

class Mailer extends Component
{
const EVENT_MESSAGE_SENT = 'messageSent';

public function send($message)
{
// ...发送 $message 的逻辑...

$event = new MessageEvent;
$event->message = $message;
$this->trigger(self::EVENT_MESSAGE_SENT, $event);
}
}