Bootstrap 4.4.1导航栏下拉菜单在移动大小的窗口中不起作用

Question

在移动窗口大小下，我无法在Bootstrap 4.4.1中使用下拉功能。链接将消失，新的菜单按钮将显示，但是单击不会执行任何操作。我不确定在这里做什么。

谢谢。

HTML：

<script src="https://kit.fontawesome.com/d7c065f8cf.js" crossorigin="anonymous"></script>

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" integrity="sha384-Vkoo8x4CGsO3+Hhxv8T/Q5PaXtkKtu6ug5TOeNV6gBiFeWPGFN9MuhOf23Q9Ifjh" crossorigin="anonymous">

<nav class="navbar navbar-expand-lg navbar-light fixed-top" id="navbar">
        <!--Navbar-->
        <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav">
            <span class="navbar-toggler-icon"></span>
          </button>
        <div class="collapse navbar-collapse" id="navbarNav">
            <ul class="navbar-nav">
                <li class="nav-item">
                    <a class="nav-link" href="#about">About</a>
                </li>
                <li class="nav-item">
                    <a class="nav-link" href="#portfolio">Portfolio</a>
                </li>
                <li class="nav-item">
                    <a class="nav-link" href="https://medium.com/@luccampbell" target="_blank">Journal <i class="fas fa-external-link-alt"></i></a>
                </li>
                <li class="nav-item">
                    <a class="nav-link" href="#contact">Contact</a>
                </li>
            </ul>
        </div>
    </nav>

CSS：

/*General navbar style & hide on scroll up transition*/
.navbar {
    background-color: #f7f7f7;
    transition: top .2s;
    font-family: 'Manrope', sans-serif;
}

/*Individual items in navbar*/
.nav-item {
    padding-left: 20px;
    padding-right: 20px;
}

/*Centering the navbar*/
.navbar-nav {
    margin-left: auto;
    margin-right: auto;
}

/*'External' icon in the navbar*/
.fa-external-link-alt {
    font-size: 10px;
    vertical-align: text-top;
}

Answer 1

您需要将脚本标签添加到html中

<script src="https://code.jquery.com/jquery-3.4.1.slim.min.js" integrity="sha384-J6qa4849blE2+poT4WnyKhv5vZF5SrPo0iEjwBvKU7imGFAV0wwj1yYfoRSJoZ+n" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/umd/popper.min.js" integrity="sha384-Q6E9RHvbIyZFJoft+2mJbHaEWldlvI9IOYy5n3zV9zzTtmI3UksdQRVvoxMfooAo" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js" integrity="sha384-wfSDF2E50Y2D1uUdj0O3uMBJnjuUD4Ih7YwaYd1iqfktj0Uod8GCExl3Og8ifwB6" crossorigin="anonymous"></script>

这是工作示例

/*General navbar style & hide on scroll up transition*/
.navbar {
    background-color: #f7f7f7;
    transition: top .2s;
    font-family: 'Manrope', sans-serif;
}

/*Individual items in navbar*/
.nav-item {
    padding-left: 20px;
    padding-right: 20px;
}

/*Centering the navbar*/
.navbar-nav {
    margin-left: auto;
    margin-right: auto;
}

/*'External' icon in the navbar*/
.fa-external-link-alt {
    font-size: 10px;
    vertical-align: text-top;
}

<script src="https://kit.fontawesome.com/d7c065f8cf.js" crossorigin="anonymous"></script>
<script src="https://code.jquery.com/jquery-3.4.1.slim.min.js" integrity="sha384-J6qa4849blE2+poT4WnyKhv5vZF5SrPo0iEjwBvKU7imGFAV0wwj1yYfoRSJoZ+n" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/umd/popper.min.js" integrity="sha384-Q6E9RHvbIyZFJoft+2mJbHaEWldlvI9IOYy5n3zV9zzTtmI3UksdQRVvoxMfooAo" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js" integrity="sha384-wfSDF2E50Y2D1uUdj0O3uMBJnjuUD4Ih7YwaYd1iqfktj0Uod8GCExl3Og8ifwB6" crossorigin="anonymous"></script>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" integrity="sha384-Vkoo8x4CGsO3+Hhxv8T/Q5PaXtkKtu6ug5TOeNV6gBiFeWPGFN9MuhOf23Q9Ifjh" crossorigin="anonymous">

<nav class="navbar navbar-expand-lg navbar-light fixed-top" id="navbar">
        <!--Navbar-->
        <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav">
            <span class="navbar-toggler-icon"></span>
          </button>
        <div class="collapse navbar-collapse" id="navbarNav">
            <ul class="navbar-nav">
                <li class="nav-item">
                    <a class="nav-link" href="#about">About</a>
                </li>
                <li class="nav-item">
                    <a class="nav-link" href="#portfolio">Portfolio</a>
                </li>
                <li class="nav-item">
                    <a class="nav-link" href="https://medium.com/@luccampbell" target="_blank">Journal <i class="fas fa-external-link-alt"></i></a>
                </li>
                <li class="nav-item">
                    <a class="nav-link" href="#contact">Contact</a>
                </li>
            </ul>
        </div>
    </nav>