Bootstrap about the use of drop-down menus

You need to wrap the drop-down menu trigger and drop- .dropdown down menu in, or another position: relative; declared element.

<div class= "dropdown" >  <button class= "btn btn-default dropdown-toggle" type= "button" id= "DropdownMenu1" Data-toggle= "dropdown" aria-haspopup= "true" aria-expanded= "true" >    dropdown    <span class= "Caret" > </span>  </button>  <ul class= "Dropdown-menu" aria-labelledby= "dropdownMenu1" >    < Li><a href= "#" >Action</a></li>    <li><a href= "#" >another action</a>< /li>    <li><a href= "#" >something else here</a></li> <li><a    href= "#" >separated link</a></li>  </ul></div>

　　

• Pop up: First line replaced .dropup by class
• Right Justification: for .dropdown-menu adding .dropdown-menu-right
  

•  分割线：<li role="separator" class="divider"></li>

•     禁用：<li class="disabled"><a href="#">Disabled link</a></li>

•     标题：<li class="dropdown-header">Dropdown header</li>

Bootstrap about the use of drop-down menus