UrlManager::getUrlForShowFile

public function getUrlForShowFile(File $file, array $params = array(), $absolute = false)
{
	if(isset($params['width']) && isset($params['height']))
	{
		$params['signature'] = ParameterSigner::getImageSignature($file->getId(), $params['width'], $params['height']);
	}
	$params['ts'] = $file->getUpdateTime()->getTimestamp();
	return $this->getUrlDownloadController('showFile', array_merge($params, array('fileId' => $file->getId(), 'filename' => $file->getName())), $absolute);
}