[fw-general] How to control 'displayExceptions' in a controller?

[Dasn]

Hi guys, I'm trying to control the ErrorController via turning
on/off the 'displayExceptions' in a controller, for example:

class ViewController extends Zend_Controller_Action
{

    public function init()
    {
        /* Initialize action controller here */
        $front=$this->getFrontController();
        $front->setParam('displayExceptions', 0);
    }
}

I found the value of 'displayExceptions' was changed, but did not
have any effects. Any idea to archive this?

Thanks.