{loop subcat(0,0,0,$siteid) $r}         {php $num++}          <h3><a href="http://www.mamicode.com/{$r[url]}">{$r[catname]}</a></h3>        <a href="http://www.mamicode.com/{$r[url]}" title=""><img src="http://www.mamicode.com/sp/img/yzmlfk_96.jpg"/></a>    {pc:content action="category" catid="$r[arrchildid]" num="20" siteid="$siteid" order="listorder ASC"}{loop $data $r}    [<a href="http://www.mamicode.com/{$r[url]}">{$r[catname]}</a>]  {/loop}{/pc}   {/loop}

前一级栏目下的所有二级栏目：

{pc:content action="category" catid="$r[arrchildid]" num="20" siteid="$siteid" order="listorder ASC"}

phpcms栏目调用