我正在尝试使用引导程序构建一个带按钮的导航栏，但下拉菜单不会在点击时打开。我在正确的位置的代码中包含了bootstrap CDN链接，bootstrap css链接，ajax popper链接和jquery链接。我没有在导航栏按钮中添加任何外部CSS。这可能是什么问题？
这是一个片段：
| sed 's/^\.//'
main.js文件包含：
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<title>Page Title</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css">
<script defer src="https://use.fontawesome.com/releases/v5.0.6/js/all.js"></script>
<script src="main.js"></script>
</head>
<body>
<nav class="navbar navbar-expand-lg navbar fixed-top navbar-light bg-light">
<span class="navbar-toggler-icon"></span>
<div class="collapse navbar-collapse" id="navbarSupportedContent">
<ul class="navbar-nav mr-auto ">
<li class="nav-item">
<div class="new-pickup"> <a class="nav-link" id="new-pickup" href="#"><i class="fa fa-plus"id="add-plus" aria-hidden="true"></i>
New Pickup </a></div>
<li class="nav-item dropdown">
<div class="sms-button">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
SMS
</a>
</div>
<div class="dropdown-menu" aria-labelledby="navbarDropdown">
<a class="dropdown-item" href="#">Delivered Status</a>
<a class="dropdown-item" href="#">Log details</a>
</div>
</li>
<li class="nav-item dropdown">
<div class="email-button">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Email
</a>
</div>
<div class="dropdown-menu" aria-labelledby="navbarDropdown">
<a class="dropdown-item" href="#">Deivered Status</a>
<a class="dropdown-item" href="#">Log Status</a>
</div>
</li>
<li class="nav-item">
<div class="call-button">
<a class="nav-link" href="#"><i class="fa fa-phone fa-flip-horizontal " aria-hidden="true"></i>
Call
</a></div>
</li>
</li>
</ul>
</div>
</nav>
<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
</body>
</html>
答案 0 :(得分：2)
尝试以下代码：
选项：1
<li class="nav-item dropdown">
<div class="sms-button" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
<a class="nav-link dropdown-toggle" href="#" > SMS </a>
</div>
<div class="dropdown-menu" aria-labelledby="navbarDropdown">
<a class="dropdown-item" href="#">Delivered Status</a>
<a class="dropdown-item" href="#">Log details</a>
</div>
</li>
选项：2
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false"> Email </a>
<div class="dropdown-menu" aria-labelledby="navbarDropdown">
<a class="dropdown-item" href="#">Deivered Status</a>
<a class="dropdown-item" href="#">Log Status</a>
</div>
</li>
答案 1 :(得分：0)
这可能是因为你在那里添加了另一个div。
尝试重新排列代码，以便具有类.dropdown-toggle的元素是下一个项目。而不是div.sms-button
答案 2 :(得分：0)
添加数据切换=＆＃34;崩溃＆＃34;数据目标=＆＃34; .navbar合拢＆＃34;到您的可点击图标
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css">
<script defer src="https://use.fontawesome.com/releases/v5.0.6/js/all.js"></script>
<script src="main.js"></script>
<nav class="navbar navbar-expand-lg navbar fixed-top navbar-light bg-light">
<!--code changes here-->
<span class="navbar-toggler-icon" data-toggle="collapse" data-target=".navbar-collapse"></span>
<div class="collapse navbar-collapse" id="navbarSupportedContent">
<ul class="navbar-nav mr-auto ">
<li class="nav-item">
<div class="new-pickup"> <a class="nav-link" id="new-pickup" href="#"><i class="fa fa-plus"id="add-plus" aria-hidden="true"></i>
New Pickup </a></div>
<li class="nav-item dropdown">
<div class="sms-button">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
SMS
</a>
</div>
<div class="dropdown-menu" aria-labelledby="navbarDropdown">
<a class="dropdown-item" href="#">Delivered Status</a>
<a class="dropdown-item" href="#">Log details</a>
</div>
</li>
<li class="nav-item dropdown">
<div class="email-button">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Email
</a>
</div>
<div class="dropdown-menu" aria-labelledby="navbarDropdown">
<a class="dropdown-item" href="#">Deivered Status</a>
<a class="dropdown-item" href="#">Log Status</a>
</div>
</li>
<li class="nav-item">
<div class="call-button">
<a class="nav-link" href="#"><i class="fa fa-phone fa-flip-horizontal " aria-hidden="true"></i>
Call
</a></div>
</li>
</li>
</ul>
</div>
</nav>
<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>