SM_in_onBootstrap.php

<?php
namespace Zsend;
use Zsend\Listener;
use Zend\Mvc\MvcEvent;

class Module
{
    public function getAutoloaderConfig()
    {
        /** Autoloading config  */
    }
    public function getConfig()
    {
      /** get config code */
    }
    
    /**
     * Return the service config
     */
    public function getServiceConfig() {
       return array(
        'factories' => array(
            /** Add the SendListener class in to the service manager */
            'Zsend\Listener\SendListener' => function($servicemanager){
                /** return the object of the SendListener class (service manager injected uisng dependency injection) */
                return new Listener\SendListener(); 
            },
            ),
        );
   }
  
    /**
     * Attach the event listeners using EventManager. 
     * 
     */
    public function onBootstrap(MvcEvent $event) {
        /* get the Event Manager from the application */
        $eventManager = $event->getApplication()->getEventManager();
        /** 
        * Have the access to the service manager as follows 
        * Zsend\Listener\SendListener class implements the ListenerAggregateInterface
        */
        $SendListener_Obj = $event->getApplication()->getServiceManager()->get('Zsend\Listener\SendListener')
        /** Attach the event */
        $eventManager->attach($SendListener_Obj);
    }
}