所以我正在学习如何使用Flask(一个python模块来帮助开发HTML页面),我还包括bootstrap来创建我的导航栏,但由于某种原因,导航的下拉菜单不会下拉
这是实际的下拉菜单代码:
<!-- Navigation Bar -->
<nav class="navbar navbar-expand-lg navbar-light bg-light">
<a class="navbar-brand" href="/">Navigation</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarSupportedContent">
<ul class="navbar-nav mr-auto">
<!-- Dropdown menu -->
<li class="nav-item dropdown">
<!-- Menu Title -->
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Animals
</a>
<!-- Dropdown -->
<div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
<!-- Dinosaur Link -->
<a class="dropdown-item" href="/dinosaur_homepage">Dinosaurs</a>
<!-- Link Divider -->
<div class="dropdown-divider"></div>
<!-- Birds Link -->
<a class="dropdown-item" href="/birds_homepage">Birds</a>
</div>
</li>
</ul>
</div>
</nav>
这是整个源代码(不包括python文件):https://pastebin.com/VhrxkbYi
答案 0 :(得分:0)
在你的情况下你错过了js和css文件
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/css/bootstrap.min.css" integrity="sha384-rwoIResjU2yc3z8GV/NPeZWAv56rSmLldC3R/AZzGRnGxQQKnKkoFVhFQhNUwEyJ" crossorigin="anonymous">
<script src="https://code.jquery.com/jquery-3.1.1.slim.min.js" integrity="sha384-A7FZj7v+d/sdmMqp/nOQwliLvUsJfDHW+k9Omg/a/EheAdgtzNs3hpfag6Ed950n" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/tether/1.4.0/js/tether.min.js" integrity="sha384-DztdAPBWPRXSA/3eYEEUWrWCy7G5KFbe8fFjk5JAIxUYHKkDx6Qin1DkWx51bBrb" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/js/bootstrap.min.js" integrity="sha384-vBWWzlZJ8ea9aCX4pEW3rVHjgjt7zpkNpZk+02D9phzyeVkE+jo0ieGizqPLForn" crossorigin="anonymous"></script>
<nav class="navbar navbar-expand-lg navbar-light bg-light">
<a class="navbar-brand" href="/">Navigation</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarSupportedContent">
<ul class="navbar-nav mr-auto">
<!-- Dropdown menu -->
<li class="nav-item dropdown">
<!-- Menu Title -->
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Animals
</a>
<!-- Dropdown -->
<div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
<!-- Dinosaur Link -->
<a class="dropdown-item" href="/dinosaur_homepage">Dinosaurs</a>
<!-- Link Divider -->
<div class="dropdown-divider"></div>
<!-- Birds Link -->
<a class="dropdown-item" href="/birds_homepage">Birds</a>
</div>
</li>
</ul>
</div>
</nav>