framework/base/Controller.php
public function run($route, $params = [])
    {
        $pos = strpos($route, '/');
        if ($pos === false) {
            return $this->runAction($route, $params);
        } elseif ($pos > 0) {
            return $this->module->runAction($route, $params);
        }

        return Yii::$app->runAction(ltrim($route, '/'), $params);
    }
public function run($route, $params = [])
    {
        $pos = strpos($route, '/');
        if ($pos === false) {
            return $this->runAction($route, $params);
        } elseif ($pos > 0) {
            return $this->module->runAction($route, $params);
        }

        return Yii::$app->runAction(ltrim($route, '/'), $params);
    }
Runs a request specified in terms of a route.
The route can be either an ID of an action within this controller or a complete route consisting
of module IDs, controller ID and action ID. If the route starts with a slash '/', the parsing of
the route will start from the application; otherwise, it will start from the parent module of this controller.
@param string $route the route to be handled, e.g., 'view', 'comment/view', '/admin/comment/view'.
@param array $params the parameters to be passed to the action.
@return mixed the result of the action.
@see runAction()