使用 Bootstrap 4，为什么不显示导航栏图标栏？

Question

我是 bootstrap 4 的新手，我正在尝试创建一个响应式导航，到目前为止我创建了一个带有 class="navbar-toggler-icon" 的按钮，它应该显示一个汉堡菜单-像图标，但它不是，我不知道为什么。有人知道吗？

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
    <link rel="stylesheet" href="node_modules/bootstrap/dist/css/bootstrap.css">
</head>
<body>
<main>
<!--==================  header  =====================-->
        <nav class="navbar navbar-toggleable-sm bg-primary">
            <div class="container">
                <button class="navbar-toggler" data-toggle="collapse" data-target="#mainNav">
                    <span class="navbar-toggler-icon"></span>
                </button>
            </div>
        </nav>
<!--================== end header  =====================-->


</main>
<script src="node_modules/jquery/dist/jquery.js"></script>
<script src="node_modules/bootstrap/dist/js/bootstrap.js"></script>
</body>
</html>

顺便说一句，这些是 bootstrap 4 个 CDN： CSS:

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">

JQuery 和 JS:

<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>

Answer 1

您无法看到 hamburger 图标，因为导航栏的颜色使您无法看到它。

您应该为 navbar 颜色和 navbar 背景颜色添加类 / 样式。

<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.0-beta1/dist/css/bootstrap.min.css" rel="stylesheet"/>


<nav class="navbar navbar-toggleable-sm navbar-light bg-light">
    <div class="container">
        <a class="navbar-brand" href="#">Company Name</a>
        <button class="navbar-toggler" data-toggle="collapse" data-target="#mainNav">
            <span class="navbar-toggler-icon"></span>
        </button>
    </div>
</nav>


<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.0.0-beta1/dist/js/bootstrap.bundle.min.js"></script>

你可以看到我为你创建的codeplyhere

使用 Bootstrap 4，为什么不显示导航栏图标栏？

Using Bootstrap 4, why isn't the navbar-icon-bar being shown?

hamburger-menu

bootstrap-4

responsive