导航条下拉 - 该实例演示了如何在导航条上添加下拉菜单。 - 在线编辑器

          <!DOCTYPE html>
<html>
<head>
  <title>下拉菜单实例|蜜蜂教程(mifengjc.com)</title>
  <meta charset="utf-8">
  <style>
    ul {
      list-style-type: none;
      margin: 0;
      padding: 0;
      overflow: hidden;
      background-color: #333;
    }

    li {
      float: left;
    }

    li a,
    .dropbtn {
      display: inline-block;
      color: white;
      text-align: center;
      padding: 14px 16px;
      text-decoration: none;
    }

    li a:hover,
    .dropdown:hover .dropbtn {
      background-color: #111;
    }

    .dropdown {
      display: inline-block;
    }

    .dropdown-content {
      display: none;
      position: absolute;
      background-color: #f9f9f9;
      min-width: 160px;
      box-shadow: 0px 8px 16px 0px rgba(0, 0, 0, 0.2);
    }

    .dropdown-content a {
      color: black;
      padding: 12px 16px;
      text-decoration: none;
      display: block;
    }

    .dropdown-content a:hover {
      background-color: #f1f1f1
    }

    .dropdown:hover .dropdown-content {
      display: block;
    }
  </style>
</head>
<body>

  <ul>
    <li><a class="active" href="#home">主页</a></li>
    <li><a href="#news">新闻</a></li>
    <div class="dropdown">
      <a href="#" class="dropbtn">下拉菜单</a>
      <div class="dropdown-content">
        <a href="#">链接 1</a>
        <a href="#">链接 2</a>
        <a href="#">链接 3</a>
      </div>
    </div>
  </ul>

  <h3>导航栏上的下拉菜单</h3>
  <p>鼠标移动到 "下拉菜单" 链接先显示下拉菜单。</p>

</body>
</html>
        