Bootstrap 实例

<!doctype html>
<html lang="en">

<head>
  <meta charset="utf-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Bootstrap 实例 - 按钮</title>

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">

</head>

<body>

<div class="container">
    <h2>内嵌按钮组</h2>
    <p>内嵌按钮组创建下拉菜单：</p>
    <div class="btn-group">
      <button type="button" class="btn btn-primary">Apple</button>
      <button type="button" class="btn btn-primary">Samsung</button>
      <div class="btn-group">
        <button type="button" class="btn btn-primary dropdown-toggle" data-toggle="dropdown">
        Sony <span class="caret"></span></button>
        <ul class="dropdown-menu" role="menu">
          <li><a href="#">Tablet</a></li>
          <li><a href="#">Smartphone</a></li>
        </ul>
      </div>
    </div>
  </div>

</html>