Nested breadcrumb using zend-navigation

Questions Components & MVC
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16

hi, I’ve been trying for weeks to get to know with event manager mechanism, although there are lots of documentation out there, I couldn’t work with it. I read your example but there are few things I can’t handle.
the case is I want to add a listener which reacts to MvcEvent::EVENT_RENDER, I mean I want to get to URL and output them automatically in view template.
this is my listener in NavigationListener.php :

 namespace Blog\Events;
use Zend\EventManager\EventManagerInterface;
use Zend\EventManager\ListenerAggregateInterface;
use Zend\Mvc\MvcEvent;

class NavigationListener  implements ListenerAggregateInterface
{
    protected $listener;
    public function attach(EventManagerInterface $events,$priority = 1){
        $shared = $events->getSharedManager();
        $shared->attach('Zend\Mvc\View\Console\DefaultRenderingStrategy',
            MvcEvent::EVENT_RENDER,[$this,'addParams']
            ,1000);
        //$this->listener[] = $events->attach(MvcEvent::EVENT_RENDER
          //  ,[$this,'addParams']
            //,1000);
    }
    public function detach(EventManagerInterface $events){}
    public function addParams(MvcEvent $event){
        // Get request URI
        $uri = $event->getResult()->getUri();
        return $uri;
    }
}

first of all, I know when we want to listen to a private Event we have to use shared event manager, is this particular event private?
second of all, is it a MUST to register this listener via onBootstrap() or init() methods?
I put this code in module.config.php of my module:

'service_manager' => [
    
    'invokables'=>[
        Events\NavigationListener::class => Events\NavigationListener::class,
    ]
],
'listeners'=> [
    Events\NavigationListener::class,
],

how should I know what are MvcEvent::EVENT_RENDER parameters? what is the target of this event that is to set as Identifires(I used ‘Zend\Mvc\View\Console\DefaultRenderingStrategy’)?
how to get the return value in the listener method at the end?