$this->context->controller->addCss not working

[phinq1910]

I have create a module on prestashop 1.7

I have using addCss on hookActionFrontControllerSetMedia but seems it not working. Why?!

public function hookActionFrontControllerSetMedia($params)
	{	

		$this->context->controller->addCss(_PS_BASE_URL_.__PS_BASE_URI__.'/imymodule/css/prestashop.css', 'all');
	} 

Please help,

Thank you

Edited November 16, 2016 by phinq1910 (see edit history)

[phinq1910]

I have using $this->context->controller->registerStylesheet and it work