Question

我不知道为什么我在设置导航栏下拉菜时遇到很多问题。它说popper没有定义和意外的令牌支持。下面的代码只是文档中的示例。请帮助我，真的很令人沮丧。

<!DOCTYPE html>
<html>
    <head>
        <link rel="stylesheet" type="text/css"  href="style.css" />
        <link href="https://fonts.googleapis.com/css?family=Source+Sans+Pro" rel="stylesheet">
        <link href="bootstrap/css/bootstrap.min.css" rel="stylesheet">
        <script type="text/javascript" src="jquery.min.js"></script>
        <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.6/popper.min.js"></script>
        <script type="text/javascript" src="bootstrap/js/bootstrap.min.js"></script>

    </head>
    <body>

        <nav class="navbar navbar-expand-lg navbar-light bg-light">
            <a class="navbar-brand" href="#">Navbar</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">
                    <li class="nav-item active">
                        <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
                    </li>
                    <li class="nav-item">
                        <a class="nav-link" href="#">Link</a>
                    </li>
                    <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">
                            Dropdown
                        </a>
                        <div class="dropdown-menu" aria-labelledby="navbarDropdown">
                            <a class="dropdown-item" href="#">Action</a>
                            <a class="dropdown-item" href="#">Another action</a>
                            <div class="dropdown-divider"></div>
                            <a class="dropdown-item" href="#">Something else here</a>
                        </div>
                    </li>
                    <li class="nav-item">
                        <a class="nav-link disabled" href="#">Disabled</a>
                    </li>
                </ul>
                <form class="form-inline my-2 my-lg-0">
                    <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
                    <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
                </form>
            </div>
        </nav>
      </body>

</html>

Answer 1

您使用的是什么bootstrap版本您可以尝试在此Web的头部添加此代码，并替换您正在使用的引导程序。

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/css/bootstrap.min.css" integrity="sha384-PsH8R72JQ3SOdhVi3uxftmaW6Vc51MKb0q5P2rRUpPvrszuE4W1povHYgTpBfshb" crossorigin="anonymous">

<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/js/bootstrap.min.js" integrity="sha384-alpBpkh1PFOepccYVYDB4do5UnbKysX5WZXm3XxPqe5iKTfUKjNkCk9SaVuEZflJ" crossorigin="anonymous"></script>

Bootstrap下拉列表需要Popper.js

https://www.codeply.com/go/ENrIDOUDtc

Bootstrap 4 navbarDropdown不起作用？

1 个答案: