<div?class="dropdown">
????<button?class="btn?btn-danger?dropdown-toggle"?type="button"?data-toggle="dropdown">食物
????<span?class="caret"></span>
????</button>
????<ul?class="dropdown-menu?dropdown-menu-right">
????????<li?class="dropdown-header?pull-left"><a?href="#">水果</a></li>
????????<li?><a?href="#">蘋果</a></li>
????????<li?><a?href="#">香蕉</a></li>
????????<li?><a?href="#">桃子</a></li>
????????<li?class="divider"><a?href="#"></a></li>
????????<li?class="dropdown-header"><a?href="#">蔬菜</a></li>
????????<li?><a?href="#">芹菜</a></li>
????????<li?><a?href="#">蘿卜</a></li>
????????<li?><a?href="#">黃瓜</a></li>
????</ul>
</div>

這樣設置以后 dropdown-header的默認左右padding會造成 header不能靠左顯示需要求改padding