<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap 实例</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.2/dist/css/bootstrap.min.css" rel="stylesheet">
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.1.2/dist/js/bootstrap.bundle.min.js"></script>
</head>
<body>
<div class="container mt-3">
<h3>带下拉按钮的输入组</h3>
<p>在输入组中添加下拉按钮。请注意，您不需要像往常一样的 .dropdown 包装器。</p>
<div class="input-group mt-3 mb-3">
<button type="button" class="btn btn-primary dropdown-toggle" data-bs-toggle="dropdown">
下拉按钮
</button>
<ul class="dropdown-menu">
<li><a class="dropdown-item" href="#">链接 1</a></li>
<li><a class="dropdown-item" href="#">链接 2</a></li>
<li><a class="dropdown-item" href="#">链接 3</a></li>
</ul>
<input type="text" class="form-control" placeholder="用户名">
</div>
</div>
</body>
</html>