Bootstrap4：导航栏切换按钮不起作用答案

【问题标题】：Bootstrap4: NavBar toggle button does not workBootstrap4：导航栏切换按钮不起作用
【发布时间】：2020-06-24 22:03:52
【问题描述】：

在缩小窗口大小时，导航栏上的按钮会消失，并且切换按钮会显示，但无法显示下拉菜单 jQuery 和其他东西的链接是从 Bootstrap 网站复制粘贴的与引导链接相同

<!DOCTYPE html>
{% load static %}
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>29er team POL</title>
    <script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" integrity="sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj" crossorigin="anonymous"></script>
    <script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js" integrity="sha384-Q6E9RHvbIyZFJoft+2mJbHaEWldlvI9IOYy5n3zV9zzTtmI3UksdQRVvoxMfooAo" crossorigin="anonymous"></script>
    <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/js/bootstrap.min.js" integrity="sha384-OgVRvuATP1z7JjHLkuOU7Xw704+h835Lr+6QL9UvYjZE3Ipu6Tp75j7Bh/kR0JKI" crossorigin="anonymous"></script>
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/css/bootstrap.min.css" integrity="sha384-9aIt2nRpC12Uk9gS9baDl411NQApFmC26EwAOH8WgZl5MYYxFfc+NcPb1dKGj7Sk" crossorigin="anonymous">
    <link rel="stylesheet" href="{% static 'css/my_style.css' %}"/>

</head>
<body>
<div class="jumbotron">
    <div class="container">
        <nav class="navbar navbar-expand-md navbar-light bg-light">
            <a class="navbar-brand" href="{% url 'index' %}">
                <img src="{% static 'images/logo_1.png' %}" width="100" height="60" alt="">
            </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="navbarNav">
                <ul class="navbar-nav">
                    <li class="nav-item active">
                        <a class="nav-link" href="{% url 'homepage:klasa' %}">Klasa 29er</a>
                    </li>
                    <li class="nav-item active">
                        <a class="nav-link" href="{% url 'homepage:kluby' %}">Kluby</a>
                    </li>
                    <li class="nav-item active">
                        <a class="nav-link" href="{% url 'homepage:kalendarz' %}">Kalendarz regat</a>
                    </li>
                    <li class="nav-item active">
                        <a class="nav-link" href="#">Archiwum wyników</a>
                    </li>
                    </li>
                    <li class="nav-item active">
                        <a class="nav-link" href="#">coś</a>
                    </li>

                </ul>
            </div>
        </nav>
    </div>

</div>

</body>
</html>

【问题讨论】：

标签： javascript html css bootstrap-4

【解决方案1】：

在<button> 上，您有 data-target="#navbarSupportedContent" 但没有具有该 ID 的 div

将其更改为：

<div class="collapse navbar-collapse" id="navbarNav">

改成：

  <div class="collapse navbar-collapse" id="navbarSupportedContent">

完整的sn-p：

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.0/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.0/js/bootstrap.min.js"></script>

<nav class="navbar navbar-expand-md navbar-light bg-light">
  <a class="navbar-brand" href="{% url 'index' %}">
    <img src="{% static 'images/logo_1.png' %}" width="100" height="60" alt="">
  </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">
      <li class="nav-item active">
        <a class="nav-link" href="{% url 'homepage:klasa' %}">Klasa 29er</a>
      </li>
      <li class="nav-item active">
        <a class="nav-link" href="{% url 'homepage:kluby' %}">Kluby</a>
      </li>
      <li class="nav-item active">
        <a class="nav-link" href="{% url 'homepage:kalendarz' %}">Kalendarz regat</a>
      </li>
      <li class="nav-item active">
        <a class="nav-link" href="#">Archiwum wyników</a>
      </li>
      <li class="nav-item active">
        <a class="nav-link" href="#">coś</a>
      </li>

    </ul>
  </div>
</nav>

【讨论】：