/**
* 渲染验证码图像。
*/
protected function renderImage()
{
if (!isset($this->imageOptions['id'])) {
$this->imageOptions['id'] = $this->getId();
}
$url = $this->getController()->createUrl($this->captchaAction, array('v' => uniqid()));
$alt = isset($this->imageOptions['alt']) ? $this->imageOptions['alt'] : '';
echo Html::image($url, $alt, $this->imageOptions);
}
