编程字典

源代码

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>编程字典</title>
  <style>
    .dropbtn {
        background-color: #4CAF50;
        color: white;
        padding: 16px;
        font-size: 16px;
        border: none;
        cursor: pointer;
    }

.dropdown {
        position: relative;
        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;
    }

.dropdown:hover .dropbtn {
        background-color: #3e8e41;
    }
  </style>
</head>
<body>

<h2>下拉菜单</h2>
  <p>鼠标移到按钮打开下拉菜单.</p>

<div class="dropdown">
    <button class="dropbtn">Dropdown</button>
    <div class="dropdown-content">
      <a href="#">Link 1</a>
      <a href="#">Link 2</a>
      <a href="#">Link 3</a>
    </div>
  </div>

</body>
</html>

运行结果