代码示例：（标识：bs_spinners_buttons）
<!DOCTYPE html>
<html>
<head>
<title>Bootstrap Example</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link href="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/5.1.2/css/bootstrap.min.css" rel="stylesheet">
<script src="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/5.1.2/js/bootstrap.min.js"></script>
</head>
<body>
<div style="padding:20px;">
<h2>加载器按钮</h2>
<p>向按钮添加加载器：</p>
<button class="btn btn-primary">
<span class="spinner-border spinner-border-sm"></span>
</button>
<button class="btn btn-primary">
<span class="spinner-border spinner-border-sm"></span>
Loading..
</button>
<button class="btn btn-primary" disabled>
<span class="spinner-border spinner-border-sm"></span>
Loading..
</button>
<button class="btn btn-primary" disabled>
<span class="spinner-grow spinner-grow-sm"></span>
Loading..
</button>
</div>
</body>
</html>
