我怎样才能使下拉菜单引导到底部的导航栏答案

【问题标题】：How can i make dropup to bootstrap navbar which is on the bottom我怎样才能使下拉菜单引导到底部的导航栏
【发布时间】：2020-04-19 19:07:49
【问题描述】：

我有这个导航栏。在里面的第三个 li 我还有另外三个链接元素。我尝试在该 ul 上添加 dropup 类，但它不起作用。当我悬停时它仍然没有弹出。

<nav class="navbar navbar-expand-lg navbar-light bg-light">
    <a class="navbar-brand" href="#"></a>
    <div class="header-logo header-logo--img">
        <a href="index.html"><img src="assets/img/ht-logo.svg" srcset="assets/img/ht-logo.svg" alt="nec"></a>
    </div>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-placement="top" data-target="#navbarNavDropdown" aria-controls="navbarNavDropdown" aria-expanded="false" aria-label="Toggle navigation">
        <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarNavDropdown">
        <ul class="navbar-nav">
            <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="#">Register</a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="#">Profile</a>
            </li>

            <li class="nav-item dropdown">
                <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenuLink" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                    <svg role="img" class="cus">
                        <use xlink:href="assets/img/nec.svg#account" />
                    </svg>
                    <span class="">&#8963;</span>
                </a>
                <div class="dropdown-menu dropup" aria-labelledby="navbarDropdownMenuLink">
                    <a class="dropdown-item" href="#">Home</a>
                    <a class="dropdown-item" href="#">Register</a>
                    <a class="dropdown-item" href="#">Profile</a>
                </div>
            </li>
        </ul>
    </div>
</nav>

【问题讨论】：

标签： html css twitter-bootstrap bootstrap-4

【解决方案1】：

对于下拉工作，您需要添加jQuery、popper.js 和bootstrap.js。

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css">

<nav class="navbar navbar-expand-lg navbar-light bg-light">
    <a class="navbar-brand" href="#"></a>
    <div class="header-logo header-logo--img">
        <a href="index.html"><img src="assets/img/ht-logo.svg" srcset="assets/img/ht-logo.svg" alt="nec"></a>
    </div>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-placement="top" data-target="#navbarNavDropdown" aria-controls="navbarNavDropdown" aria-expanded="false" aria-label="Toggle navigation">
        <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarNavDropdown">
        <ul class="navbar-nav">
            <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="#">Register</a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="#">Profile</a>
            </li>

            <li class="nav-item dropdown">
                <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenuLink" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                    <svg role="img" class="cus">
                        <use xlink:href="assets/img/nec.svg#account" />
                    </svg>
                    <span class="">&#8963;</span>
                </a>
                <div class="dropdown-menu dropup" aria-labelledby="navbarDropdownMenuLink">
                    <a class="dropdown-item" href="#">Home</a>
                    <a class="dropdown-item" href="#">Register</a>
                    <a class="dropdown-item" href="#">Profile</a>
                </div>
            </li>
        </ul>
    </div>
</nav>

<script src="https://code.jquery.com/jquery-3.4.1.slim.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js"></script>

【讨论】：

【解决方案2】：

只需在它自己的导航上添加下拉类

在我的情况下

【讨论】：