Bootstrap 4 navbar-toggler-icon 不出现

Question

访问：https://jsfiddle.net/8tpm4z00/

<div class="container">

  <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#myNavigation" aria-controls="myNavigation" aria-expanded="false" aria-label="Toggle navigation">
  <span class="navbar-toggler-icon"></span>
  </button>

  <a href="#" class="navbar-brand">KP</a>

  <div class="collapse navbar-collapse" id="myNavigation">
      <div class="navbar-nav">
        <a class="p-3 nav-item nav-link active " href="#">Home</a>
        <a class="p-3 nav-item nav-link " href="#">About</a>
        <a class="p-3 nav-item nav-link " href="#">Contact Me</a>
      </div><!-- <div class="navbar-nav"> -->
  </div><!-- <div class="collapse navbar-collapse"> -->

</div><!-- <div class="container"> -->

当菜单折叠以实现移动响应时，.navbar-toggler-icon 不会出现在导航栏切换按钮上。

我已经搜索过这个问题并调整了 jquery 和 bootstrap 链接。通过将 jquery 链接放在 bootstrap 4 链接之上。但这似乎不起作用。外部库在我的 HTML 中的链接顺序与 jsfiddle 相同。

Answer 1

更新：

navbar-inverse 在 B4 版本中不再可用，您可以改用navbar-dark。

---

使用navbar-inverse bg-inverse 代替.navbar-default

<section role="navigation">
  <nav class="navbar navbar-inverse bg-inverse navbar-toggleable-sm fixed-top"><!-- navbar-inverse -->

    <div class="container">

      <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#myNavigation" aria-controls="myNavigation" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
      </button>

      <a href="#" class="navbar-brand">KP</a>

      <div class="collapse navbar-collapse" id="myNavigation">
          <div class="navbar-nav">
            <a class="p-3 nav-item nav-link active " href="#">Home</a>
            <a class="p-3 nav-item nav-link " href="#">About</a>
            <a class="p-3 nav-item nav-link " href="#">Contact Me</a>
          </div><!-- <div class="navbar-nav"> -->
      </div><!-- <div class="collapse navbar-collapse"> -->

    </div><!-- <div class="container"> -->

  </nav>
</section>

Updated fiddle

Answer 2

如果你使用 bootstrap 4 beta：

您只能在 nav 标签中添加 navbar-dark 类。

结果：

<nav class = "navbar navbar-expand-lg navbar-dark fixed-top navbar-default" role = "navigation">
     <a class="navbar-brand" href="#">
         <img class = "img-responsive logo" src = "~/Content/Images/ogo__160x36.png" alt = "" />
     </a>
     <button type = "button" class = "navbar-toggler" data-toggle = "collapse" data-target = "#menuPrincipal" aria-controls = "navbarNav" aria-expanded = "false" aria-label = "Toggle navigation ">
         <span class = "navbar-toggler-icon"> </ span>
     </button>
     <div class="collapse navbar-collapse" ...>...</div>
</nav>

Answer 3

如果你不使用 navbar-light 或 dark 设置 background-img 一些图像到 .navbar-toggler-icon 如下

.navbar-toggler-icon {
background-image: url(data:image/svg+xml,%3csvg viewBox='0 0 30 30' xmlns='http://www.w3.org/2000…p='round' stroke-miterlimit='10' d='M47h22M4 15h22M423h22'/%3e%3c/svg%3e);
}

或使用字体 awsome 中的 fa-bars

Answer 4

使用 navbar-dark 代替 navbar-inverse 和 bg-dark 代替 bg-inverse

  <nav class="navbar navbar-dark navbar-expand-md bg-dark ">