下拉菜單不能用
<!DOCTYPE?html>
<html?lang="en">
<head>
????<meta?charset="UTF-8">
????<title>下拉菜單</title>
????<!--?最新版本的?Bootstrap?核心?CSS?文件?-->
<link?rel="stylesheet"?>
<!--?可選的?Bootstrap?主題文件（一般不用引入）?-->
<link?rel="stylesheet"?>
<!--?最新的?Bootstrap?核心?JavaScript?文件?-->
<script?src="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/js/bootstrap.min.js"?integrity="sha384-aJ21OjlMXNL5UyIl/XNwTMqvzeRMZH2w8c5cRVpzpU8Y5bApTppSuUkhZXN0VxHd"?crossorigin="anonymous"></script>
</head>
<body>
????<div?class="dropdown">
????????<button?class="btn?btn-default?dropdown-toggle"?data-toggle="dropdown">
????????????<span?class="caret"></span>
????????????這是按鈕
????????</button>
????????<ul?class="dropdown-menu">
????????????
????????????<li>
????????????????<a?>
????????????????????百度
????????????????</a>
????????????</li>
????????</ul>
????</div>
????
????
</body>
</html>
2021-12-22
cdn改地址了
2021-10-21
這個引用的有問題了