<ul class="menu">
    <li{leaf:if $index} class="active"{/leaf:if}><a href="{leaf.site.url}">首页</a></li>
    {leaf:nav }
    <li class="{leaf:if $nav[child]}dropdown{/leaf:if}{leaf:if $on} active{/leaf:if}">
        {leaf:if $nav[child]}
        <div class="dropdown-box">
            {leaf:nav parent_id=$nav[id]}
            <p><a href="{leaf.nav.url}">{leaf.nav.name}</a></p>
            {/leaf:nav}
        </div>
        {/leaf:if}
    </li>
    {/leaf:nav}
</ul>