bootstrap导航条的二级菜单下实现三级菜单

bootstrap在导航条中的二级菜单下实现三级菜单

modify by 20180506 add music

border="0" width="330" height="86" src="//music.163.com/outchain/player?type=2&id=446177349&auto=1&height=66">

update 20180919:
推广下自己的公众号，打算以后系列文章会维护在微信公众号上，有兴趣的朋友可以关注哟，多数系列文章可能会围绕python系列进行展开：

直接上代码

<!--html里的写法，直接搭好bootstrap导航条结构
  这里就用美食来做例子吧-->



    <!--反色的导航条-->
    <nav class="navbar navbar-inverse navbar-fixed-top" role="navigation">
      <div class="container-fluid">
        <!-- Brand and toggle get grouped for better mobile display -->
        <div class="navbar-header">
          <button type="button" class="navbar-toggle collapsed" data-
          toggle="collapse" data-target="#bs-example-navbar-collapse-1">
                  <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="#">
                  美食之家  <span class="glyphicon glyphicon-cutlery"></span>
                </a>
        </div>

        <!-- Collect the nav links, forms, and other content for toggling -->
        <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
          <ul class="nav navbar-nav">
            <li><a href="#">首页</a></li>
            <li class="dropdown">
              <a href="#" class="dropdown-toggle" data-toggle="dropdown">菜谱 
              <span class="caret"></span></a>
              <ul class="dropdown-menu" role="menu">
                <li class="dropdown-submenu">  
                  <a href="#">主食</a>
                  <ul class="dropdown-menu">  
                    <li><a href="#">饭</a></li>  
                                <li><a href="#">饼</a></li>  
                                <li><a href="#">包子</a></li>
                            </ul>  
                </li>
                <li><a href="#">肉类</a></li>
                <li><a href="#">水产</a></li>
              </ul>
            </li>
            <li><a href="#">食材</a></li>
            <li><a href="#">健康</a></li>
            <li><a href="#">话题</a></li>
            <li><a href="#">活动</a></li>
          </ul>
</nav>

<!--CSS样式-->

    <style>
      body {
        padding-top: 70px;
      }
      
      
      
      /*自定义的css*/
      .dropdown-submenu {
        position: relative;
      }
      
      .dropdown-submenu>.dropdown-menu {
        top: 0;
        left: 100%;
        margin-top: -6px;
        margin-left: -1px;
        -webkit-border-radius: 0 6px 6px 6px;
        -moz-border-radius: 0 6px 6px;
        border-radius: 0 6px 6px 6px;
      }
      
      .dropdown-submenu:hover>.dropdown-menu {
        display: block;
      }
      
      .dropdown-submenu>a:after {
        display: block;
        content: " ";
        float: right;
        width: 0;
        height: 0;
        border-color: transparent;
        border-style: solid;
        border-width: 5px 0 5px 5px;
        border-left-color: #ccc;
        margin-top: 5px;
        margin-right: -10px;
      }
      
      .dropdown-submenu:hover>a:after {
        border-left-color: #fff;
      }
      
      .dropdown-submenu.pull-left {
        float: none;
      }
      
      .dropdown-submenu.pull-left>.dropdown-menu {
        left: -100%;
        margin-left: 10px;
        -webkit-border-radius: 6px 0 6px 6px;
        -moz-border-radius: 6px 0 6px 6px;
        border-radius: 6px 0 6px 6px;
      }
    </style>