导航条

1.示例

<!-- Fixed navbar -->
<nav class="navbar navbar-default navbar-fixed-top">
  <div class="container">
	<div class="navbar-header">
	  <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar" aria-expanded="false" aria-controls="navbar">
		<span class="sr-only">Toggle navigation</span>
		<span class="icon-bar"></span>
		<span class="icon-bar"></span>
		<span class="icon-bar"></span>
	  </button>
	  <a class="navbar-brand" href="#">Project name</a>
	</div>
	<div id="navbar" class="navbar-collapse collapse">
	  <ul class="nav navbar-nav">
		<li class="active"><a href="#">Home</a></li>
		<li><a href="#about">About</a></li>
		<li><a href="#contact">Contact</a></li>
		<li class="dropdown">
		  <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Dropdown <span class="caret"></span></a>
		  <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 class="dropdown-header">Nav header</li>
			<li><a href="#">Separated link</a></li>
			<li><a href="#">One more separated link</a></li>
		  </ul>
		</li>
	  </ul>
	  <ul class="nav navbar-nav navbar-right">
		<li><a href="../navbar/">Default</a></li>
		<li><a href="../navbar-static-top/">Static top</a></li>
		<li class="active"><a href="./">Fixed top <span class="sr-only">(current)</span></a></li>
	  </ul>
	</div><!--/.nav-collapse -->
  </div>
</nav>

　　

效果：http://v3.bootcss.com/examples/navbar-fixed-top/

2.主要类

2.1 navbar-fixed-top/navbar-fixed-bottom

主要将导航条固定在顶端/底部，随着页面的滑动，导航条一直在视野里。

2.2 navbar-right

将元素显示在右侧。

3.2 navbar-inverse

导航条背景色反色显示。

end