Typecho 导航子类多层分类

Typecho 导航子类多层分类教程，在适当位置插入下列代码，一般是在header.php文件，CSS效果要自己写下：

 <?php $this->widget('Widget_Metas_Category_List')->to($categorys); ?>
 <?php while($categorys->next()): ?>
 <?php if ($categorys->levels === 0): ?>
 <?php $children = $categorys->getAllChildren($categorys->mid); ?>
 <?php if (empty($children)) { ?>
 <li <?php if($this->is('category', $categorys->slug)): ?> class="active"<?php endif; ?>>
    <a href="<?php $categorys->permalink(); ?>" title="<?php $categorys->name(); ?>"><?php $categorys->name(); ?></a>
</li>
<?php } else { ?>
<li >
    <a  data-toggle="dropdown" href="#" data-target="#"><?php $categorys->name(); ?></a>
    <ul class="png">
        <?php foreach ($children as $mid) { ?>
        <?php $child = $categorys->getCategory($mid); ?>
        <li <?php if($this->is('category', $mid)): ?> class="active"<?php endif; ?>>
            <a href="<?php echo $child['permalink'] ?>" title="<?php echo $child['name']; ?>"><?php echo $child['name']; ?></a>
        </li>
        <?php } ?>
    </ul>
</li>
<?php } ?>
<?php endif; ?>
<?php endwhile; ?>

效果图