<div?class="btn-group">
??<button?type="button"?class="btn?btn-default?dropdown-toggle"?data-toggle="dropdown"?aria-haspopup="true"?aria-expanded="false">
????Action?<span?class="caret"></span>
??</button>
??<ul?class="dropdown-menu">
????<li><a?href="#">Action</a></li>
????<li><a?href="#">Another?action</a></li>
????<li><a?href="#">Something?else?here</a></li>
????<li?role="separator"?class="divider"></li>
????<li><a?href="#">Separated?link</a></li>

歡迎采納