/**
* 输出缩略图
*/
public function action_default($type = '')
{
$width = 80;
$height = 30;
if ($type && preg_match('#^([0-9]+)x([0-9]+)$#i', $type, $m)) {
if ($m[1] > 0) {
$width = $m[1];
}
if ($m[1] > 0) {
$height = $m[2];
}
}
Captcha::render(array('width' => $width, 'height' => $height));
}