在action中修改render函数参数，添加第三个参数，设置为true

文档：

public string render(string $view, array $data=NULL, boolean $return=false)
$view string name of the view to be rendered. See getViewFile for details about how the view script is resolved.
$data array data to be extracted into PHP variables and made available to the view script
$return boolean whether the rendering result should be returned instead of being displayed to end users.
{return} string the rendering result. Null if the rendering result is not required.

$out_file = $this->render($view,$data,true);

save_to_html($path, $out_file) ;//此函数仅仅是示例，具体实现自己写。把$out_file存到指定目录，自己命名

unset($outFile);