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导航栏

Bootstrap 强大的响应式导航标题导航栏的文档和示例。包括对品牌、导航等的支持，包括对我们的折叠插件的支持。

在此页

怎么运行的

在开始使用导航栏之前，您需要了解以下内容：

  • 导航栏需要一个 wrapping .navbarwith.navbar-expand{-sm|-md|-lg|-xl|-xxl}响应式折叠和配色方案类。
  • 默认情况下，导航栏及其内容是流动的。更改容器以不同方式限制其水平宽度。
  • 使用我们的spacing和flex实用程序类来控制导航栏中的间距和对齐方式。
  • 默认情况下，导航栏是响应式的，但您可以轻松修改它们以更改它。响应行为取决于我们的 Collapse JavaScript 插件。
  • 通过使用<nav>元素确保可访问性，或者，如果使用更通用的元素（例如 a <div>），请将 a 添加role="navigation"到每个导航栏以明确将其标识为辅助技术用户的地标区域。
  • 通过aria-current="page"用于当前页面或aria-current="true"集合中的当前项目来指示当前项目。
  • v5.2.0 中的新功能：导航栏可以使用作用域为.navbar基类的 CSS 变量作为主题。.navbar-light已被弃用.navbar-dark并被重写以覆盖 CSS 变量而不是添加额外的样式。
该组件的动画效果依赖于prefers-reduced-motion媒体查询。请参阅我们的辅助功能文档的减少运动部分。

支持的内容

导航栏内置了对少数子组件的支持。根据需要从以下选项中选择：

  • .navbar-brand为您的公司、产品或项目名称。
  • .navbar-nav用于全高度和轻量级导航（包括对下拉菜单的支持）。
  • .navbar-toggler用于我们的折叠插件和其他导航切换行为。
  • 用于任何表单控件和操作的 Flex 和间距实用程序。
  • .navbar-text用于添加垂直居中的文本字符串。
  • .collapse.navbar-collapse用于按父断点分组和隐藏导航栏内容。
  • 添加一个选项.navbar-scroll来设置max-height和滚动展开的导航栏内容。

这是响应式浅色主题导航栏中包含的所有子组件的示例，该导航栏会在lg（大）断点处自动折叠。

HTML代码 
<nav class="navbar navbar-expand-lg bg-body-tertiary">
  <div class="container-fluid">
    <a class="navbar-brand" href="#">Navbar</a>
    <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-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 me-auto mb-2 mb-lg-0">
        <li class="nav-item">
          <a class="nav-link active" aria-current="page" href="#">Home</a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Link</a>
        </li>
        <li class="nav-item dropdown">
          <a class="nav-link dropdown-toggle" href="#" role="button" data-bs-toggle="dropdown" aria-expanded="false">
            Dropdown
          </a>
          <ul class="dropdown-menu">
            <li><a class="dropdown-item" href="#">Action</a></li>
            <li><a class="dropdown-item" href="#">Another action</a></li>
            <li><hr class="dropdown-divider"></li>
            <li><a class="dropdown-item" href="#">Something else here</a></li>
          </ul>
        </li>
        <li class="nav-item">
          <a class="nav-link disabled">Disabled</a>
        </li>
      </ul>
      <form class="d-flex" role="search">
        <input class="form-control me-2" type="search" placeholder="Search" aria-label="Search">
        <button class="btn btn-outline-success" type="submit">Search</button>
      </form>
    </div>
  </div>
</nav>

此示例使用背景( bg-body-tertiary) 和间距( me-auto, mb-2, mb-lg-0, me-2) 实用程序类。

品牌

.navbar-brand可以应用于大多数元素，但锚点效果最好，因为某些元素可能需要实用程序类或自定义样式。

文本

在具有.navbar-brand该类的元素中添加您的文本。

HTML代码 
<!-- As a link -->
<nav class="navbar bg-body-tertiary">
  <div class="container-fluid">
    <a class="navbar-brand" href="#">Navbar</a>
  </div>
</nav>

<!-- As a heading -->
<nav class="navbar bg-body-tertiary">
  <div class="container-fluid">
    <span class="navbar-brand mb-0 h1">Navbar</span>
  </div>
</nav>

图片

您可以将 中的文本替换.navbar-brand为<img>。

HTML代码 
<nav class="navbar bg-body-tertiary">
  <div class="container">
    <a class="navbar-brand" href="#">
      <img src="/assets/brand/bootstrap-logo.svg" alt="Bootstrap" width="30" height="24">
    </a>
  </div>
</nav>

图片和文字

您还可以使用一些额外的实用程序同时添加图像和文本。.d-inline-block请注意.align-text-top在<img>.

HTML代码 
<nav class="navbar bg-body-tertiary">
  <div class="container-fluid">
    <a class="navbar-brand" href="#">
      <img src="/assets/brand/bootstrap-logo.svg" alt="Logo" width="30" height="24" class="d-inline-block align-text-top">
      Bootstrap
    </a>
  </div>
</nav>

导航栏导航链接建立在我们的.nav选项之上，带有自己的修饰符类，并且需要使用切换器类来实现适当的响应式样式。导航栏中的导航也将增长以占据尽可能多的水平空间，以保持导航栏内容安全对齐。

添加.active类.nav-link以指示当前页面。

请注意，您还应该aria-current在 active 上添加属性.nav-link。

HTML代码 
<nav class="navbar navbar-expand-lg bg-body-tertiary">
  <div class="container-fluid">
    <a class="navbar-brand" href="#">Navbar</a>
    <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarNav" aria-controls="navbarNav" 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">
          <a class="nav-link active" aria-current="page" href="#">Home</a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Features</a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Pricing</a>
        </li>
        <li class="nav-item">
          <a class="nav-link disabled">Disabled</a>
        </li>
      </ul>
    </div>
  </div>
</nav>

因为我们为我们的导航使用类，如果你愿意，你可以完全避免基于列表的方法。

HTML代码 
<nav class="navbar navbar-expand-lg bg-body-tertiary">
  <div class="container-fluid">
    <a class="navbar-brand" href="#">Navbar</a>
    <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarNavAltMarkup" aria-controls="navbarNavAltMarkup" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarNavAltMarkup">
      <div class="navbar-nav">
        <a class="nav-link active" aria-current="page" href="#">Home</a>
        <a class="nav-link" href="#">Features</a>
        <a class="nav-link" href="#">Pricing</a>
        <a class="nav-link disabled">Disabled</a>
      </div>
    </div>
  </div>
</nav>

您还可以在导航栏中使用下拉菜单。下拉菜单需要一个包装元素来定位，所以请务必使用如下所示的独立.nav-item和嵌套元素。.nav-link

HTML代码 
<nav class="navbar navbar-expand-lg bg-body-tertiary">
  <div class="container-fluid">
    <a class="navbar-brand" href="#">Navbar</a>
    <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-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">
          <a class="nav-link active" aria-current="page" href="#">Home</a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Features</a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Pricing</a>
        </li>
        <li class="nav-item dropdown">
          <a class="nav-link dropdown-toggle" href="#" role="button" data-bs-toggle="dropdown" aria-expanded="false">
            Dropdown link
          </a>
          <ul class="dropdown-menu">
            <li><a class="dropdown-item" href="#">Action</a></li>
            <li><a class="dropdown-item" href="#">Another action</a></li>
            <li><a class="dropdown-item" href="#">Something else here</a></li>
          </ul>
        </li>
      </ul>
    </div>
  </div>
</nav>

表单

在导航栏中放置各种表单控件和组件：

HTML代码 
<nav class="navbar bg-body-tertiary">
  <div class="container-fluid">
    <form class="d-flex" role="search">
      <input class="form-control me-2" type="search" placeholder="Search" aria-label="Search">
      <button class="btn btn-outline-success" type="submit">Search</button>
    </form>
  </div>
</nav>

.navbar使用 flex 布局的直接子元素将默认为justify-content: space-between. 根据需要使用其他flex 实用程序来调整此行为。

HTML代码 
<nav class="navbar bg-body-tertiary">
  <div class="container-fluid">
    <a class="navbar-brand">Navbar</a>
    <form class="d-flex" role="search">
      <input class="form-control me-2" type="search" placeholder="Search" aria-label="Search">
      <button class="btn btn-outline-success" type="submit">Search</button>
    </form>
  </div>
</nav>

输入组也起作用。如果您的导航栏是一个完整的表单，或者主要是一个表单，您可以使用该<form>元素作为容器并保存一些 HTML。

HTML代码 
<nav class="navbar bg-body-tertiary">
  <form class="container-fluid">
    <div class="input-group">
      <span class="input-group-text" id="basic-addon1">@</span>
      <input type="text" class="form-control" placeholder="Username" aria-label="Username" aria-describedby="basic-addon1">
    </div>
  </form>
</nav>

这些导航栏形式也支持各种按钮。这也是一个很好的提醒，垂直对齐实用程序可用于对齐不同大小的元素。

HTML代码 
<nav class="navbar bg-body-tertiary">
  <form class="container-fluid justify-content-start">
    <button class="btn btn-outline-success me-2" type="button">Main button</button>
    <button class="btn btn-sm btn-outline-secondary" type="button">Smaller button</button>
  </form>
</nav>

文本

导航栏可以在 . 的帮助下包含一些文本.navbar-text。此类调整文本字符串的垂直对齐方式和水平间距。

HTML代码 
<nav class="navbar bg-body-tertiary">
  <div class="container-fluid">
    <span class="navbar-text">
      Navbar text with an inline element
    </span>
  </div>
</nav>

根据需要与其他组件和实用程序混合搭配。

HTML代码 
<nav class="navbar navbar-expand-lg bg-body-tertiary">
  <div class="container-fluid">
    <a class="navbar-brand" href="#">Navbar w/ text</a>
    <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarText" aria-controls="navbarText" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarText">
      <ul class="navbar-nav me-auto mb-2 mb-lg-0">
        <li class="nav-item">
          <a class="nav-link active" aria-current="page" href="#">Home</a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Features</a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Pricing</a>
        </li>
      </ul>
      <span class="navbar-text">
        Navbar text with an inline element
      </span>
    </div>
  </div>
</nav>

配色方案

v5.3.0 中新的深色导航栏——我们已经弃用.navbar-dark了新的data-bs-theme="dark". 添加data-bs-theme="dark"到.navbar以启用特定于组件的颜色模式。详细了解我们的颜色模式。

v5.2.0 中的新功能 — Navbar 主题现在由 CSS 变量提供支持并且.navbar-light已被弃用。CSS 变量应用于.navbar，默认为“浅色”外观，并且可以被覆盖.navbar-dark。

由于 Bootstrap 结合了 Sass 和 CSS 变量，导航栏主题比以往任何时候都更容易。默认是我们的“浅色导航栏”，用于浅色背景，但您也可以申请.navbar-dark深色背景。然后，使用.bg-*实用程序进行自定义。

<nav class="navbar bg-dark" data-bs-theme="dark">
  <!-- Navbar content -->
</nav>

<nav class="navbar bg-primary" data-bs-theme="dark">
  <!-- Navbar content -->
</nav>

<nav class="navbar" style="background-color: #e3f2fd;">
  <!-- Navbar content -->
</nav>

集装箱

虽然这不是必需的，但您可以将导航栏包裹在 a.container中以使其在页面上居中——但请注意，内部容器仍然是必需的。或者您可以在 中添加一个容器，以仅将固定或静态顶部导航栏.navbar的内容居中。

HTML代码 
<div class="container">
  <nav class="navbar navbar-expand-lg bg-body-tertiary">
    <div class="container-fluid">
      <a class="navbar-brand" href="#">Navbar</a>
    </div>
  </nav>
</div>

使用任何响应式容器来更改导航栏中内容的显示宽度。

HTML代码 
<nav class="navbar navbar-expand-lg bg-body-tertiary">
  <div class="container-md">
    <a class="navbar-brand" href="#">Navbar</a>
  </div>
</nav>

放置

使用我们的位置实用程序将导航栏放置在非静态位置。从固定到顶部、固定到底部、粘到顶部（滚动页面直到到达顶部，然后停留在那里）或粘到底部（滚动到页面底部，然后停留）中选择那里）。

固定导航栏使用position: fixed，这意味着它们是从 DOM 的正常流中提取的，并且可能需要自定义 CSS（例如，padding-top在 上<body>）以防止与其他元素重叠。

HTML代码 
<nav class="navbar bg-body-tertiary">
  <div class="container-fluid">
    <a class="navbar-brand" href="#">Default</a>
  </div>
</nav>
HTML代码 
<nav class="navbar fixed-top bg-body-tertiary">
  <div class="container-fluid">
    <a class="navbar-brand" href="#">Fixed top</a>
  </div>
</nav>
HTML代码 
<nav class="navbar fixed-bottom bg-body-tertiary">
  <div class="container-fluid">
    <a class="navbar-brand" href="#">Fixed bottom</a>
  </div>
</nav>
HTML代码 
<nav class="navbar sticky-top bg-body-tertiary">
  <div class="container-fluid">
    <a class="navbar-brand" href="#">Sticky top</a>
  </div>
</nav>
HTML代码 
<nav class="navbar sticky-bottom bg-body-tertiary">
  <div class="container-fluid">
    <a class="navbar-brand" href="#">Sticky bottom</a>
  </div>
</nav>

滚动

添加.navbar-nav-scroll到.navbar-nav（或其他导航栏子组件）以在折叠的导航栏的可切换内容中启用垂直滚动。默认情况下，滚动开始75vh（或视口高度的 75%），但您可以使用本地 CSS 自定义属性--bs-navbar-height或自定义样式覆盖它。当导航栏展开时，在较大的视口中，内容将像在默认导航栏中一样显示。

请注意，此行为有一个潜在的缺点——overflow当设置overflow-y: auto（需要在此处滚动内容）时，overflow-x相当于auto，这将裁剪一些水平内容。

.navbar-nav-scroll这是一个使用with的示例导航栏style="--bs-scroll-height: 100px;"，带有一些额外的边距实用程序以获得最佳间距。

HTML代码 
<nav class="navbar navbar-expand-lg bg-body-tertiary">
  <div class="container-fluid">
    <a class="navbar-brand" href="#">Navbar scroll</a>
    <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarScroll" aria-controls="navbarScroll" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarScroll">
      <ul class="navbar-nav me-auto my-2 my-lg-0 navbar-nav-scroll" style="--bs-scroll-height: 100px;">
        <li class="nav-item">
          <a class="nav-link active" aria-current="page" href="#">Home</a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Link</a>
        </li>
        <li class="nav-item dropdown">
          <a class="nav-link dropdown-toggle" href="#" role="button" data-bs-toggle="dropdown" aria-expanded="false">
            Link
          </a>
          <ul class="dropdown-menu">
            <li><a class="dropdown-item" href="#">Action</a></li>
            <li><a class="dropdown-item" href="#">Another action</a></li>
            <li><hr class="dropdown-divider"></li>
            <li><a class="dropdown-item" href="#">Something else here</a></li>
          </ul>
        </li>
        <li class="nav-item">
          <a class="nav-link disabled">Link</a>
        </li>
      </ul>
      <form class="d-flex" role="search">
        <input class="form-control me-2" type="search" placeholder="Search" aria-label="Search">
        <button class="btn btn-outline-success" type="submit">Search</button>
      </form>
    </div>
  </div>
</nav>

响应行为

导航栏可以使用.navbar-toggler、.navbar-collapse和.navbar-expand{-sm|-md|-lg|-xl|-xxl}类来确定它们的内容何时折叠在按钮后面。结合其他实用程序，您可以轻松选择何时显示或隐藏特定元素。

对于永不折叠.navbar-expand的导航栏，在导航栏上添加类。对于总是折叠的导航栏，不要添加任何.navbar-expand类。

切换器

默认情况下，导航栏切换器是左对齐的，但如果它们跟在像 a 这样的兄弟元素.navbar-brand之后，它们将自动对齐到最右边。反转标记将反转切换器的位置。以下是不同切换样式的示例。

.navbar-brand在最小断点处没有显示：

HTML代码 
<nav class="navbar navbar-expand-lg bg-body-tertiary">
  <div class="container-fluid">
    <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarTogglerDemo01" aria-controls="navbarTogglerDemo01" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarTogglerDemo01">
      <a class="navbar-brand" href="#">Hidden brand</a>
      <ul class="navbar-nav me-auto mb-2 mb-lg-0">
        <li class="nav-item">
          <a class="nav-link active" aria-current="page" href="#">Home</a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Link</a>
        </li>
        <li class="nav-item">
          <a class="nav-link disabled">Disabled</a>
        </li>
      </ul>
      <form class="d-flex" role="search">
        <input class="form-control me-2" type="search" placeholder="Search" aria-label="Search">
        <button class="btn btn-outline-success" type="submit">Search</button>
      </form>
    </div>
  </div>
</nav>

左侧显示品牌名称，右侧显示切换器：

HTML代码 
<nav class="navbar navbar-expand-lg bg-body-tertiary">
  <div class="container-fluid">
    <a class="navbar-brand" href="#">Navbar</a>
    <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarTogglerDemo02" aria-controls="navbarTogglerDemo02" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarTogglerDemo02">
      <ul class="navbar-nav me-auto mb-2 mb-lg-0">
        <li class="nav-item">
          <a class="nav-link active" aria-current="page" href="#">Home</a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Link</a>
        </li>
        <li class="nav-item">
          <a class="nav-link disabled">Disabled</a>
        </li>
      </ul>
      <form class="d-flex" role="search">
        <input class="form-control me-2" type="search" placeholder="Search" aria-label="Search">
        <button class="btn btn-outline-success" type="submit">Search</button>
      </form>
    </div>
  </div>
</nav>

左侧带有切换器，右侧带有品牌名称：

HTML代码 
<nav class="navbar navbar-expand-lg bg-body-tertiary">
  <div class="container-fluid">
    <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarTogglerDemo03" aria-controls="navbarTogglerDemo03" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>
    <a class="navbar-brand" href="#">Navbar</a>
    <div class="collapse navbar-collapse" id="navbarTogglerDemo03">
      <ul class="navbar-nav me-auto mb-2 mb-lg-0">
        <li class="nav-item">
          <a class="nav-link active" aria-current="page" href="#">Home</a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Link</a>
        </li>
        <li class="nav-item">
          <a class="nav-link disabled">Disabled</a>
        </li>
      </ul>
      <form class="d-flex" role="search">
        <input class="form-control me-2" type="search" placeholder="Search" aria-label="Search">
        <button class="btn btn-outline-success" type="submit">Search</button>
      </form>
    </div>
  </div>
</nav>

外部内容

有时您希望使用折叠插件为结构上位于.navbar. 因为我们的插件适用于idanddata-bs-target匹配，所以很容易做到！

HTML代码 
<div class="collapse" id="navbarToggleExternalContent">
  <div class="bg-dark p-4">
    <h5 class="text-white h4">Collapsed content</h5>
    <span class="text-muted">Toggleable via the navbar brand.</span>
  </div>
</div>
<nav class="navbar navbar-dark bg-dark">
  <div class="container-fluid">
    <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarToggleExternalContent" aria-controls="navbarToggleExternalContent" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>
  </div>
</nav>

When you do this, we recommend including additional JavaScript to move the focus programmatically to the container when it is opened. Otherwise, keyboard users and users of assistive technologies will likely have a hard time finding the newly revealed content - particularly if the container that was opened comes before the toggler in the document’s structure. We also recommend making sure that the toggler has the aria-controls attribute, pointing to the id of the content container. In theory, this allows assistive technology users to jump directly from the toggler to the container it controls–but support for this is currently quite patchy.

Offcanvas

使用offcanvas 组件将展开和折叠的导航栏转换为 offcanvas 抽屉。我们扩展了 offcanvas 默认样式并使用我们的.navbar-expand-*类来创建动态且灵活的导航侧边栏。

在下面的示例中，要创建一个始终在所有断点处折叠的 offcanvas 导航栏，请.navbar-expand-*完全省略该类。

HTML代码 
<nav class="navbar bg-body-tertiary fixed-top">
  <div class="container-fluid">
    <a class="navbar-brand" href="#">Offcanvas navbar</a>
    <button class="navbar-toggler" type="button" data-bs-toggle="offcanvas" data-bs-target="#offcanvasNavbar" aria-controls="offcanvasNavbar">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="offcanvas offcanvas-end" tabindex="-1" id="offcanvasNavbar" aria-labelledby="offcanvasNavbarLabel">
      <div class="offcanvas-header">
        <h5 class="offcanvas-title" id="offcanvasNavbarLabel">Offcanvas</h5>
        <button type="button" class="btn-close" data-bs-dismiss="offcanvas" aria-label="Close"></button>
      </div>
      <div class="offcanvas-body">
        <ul class="navbar-nav justify-content-end flex-grow-1 pe-3">
          <li class="nav-item">
            <a class="nav-link active" aria-current="page" href="#">Home</a>
          </li>
          <li class="nav-item">
            <a class="nav-link" href="#">Link</a>
          </li>
          <li class="nav-item dropdown">
            <a class="nav-link dropdown-toggle" href="#" role="button" data-bs-toggle="dropdown" aria-expanded="false">
              Dropdown
            </a>
            <ul class="dropdown-menu">
              <li><a class="dropdown-item" href="#">Action</a></li>
              <li><a class="dropdown-item" href="#">Another action</a></li>
              <li>
                <hr class="dropdown-divider">
              </li>
              <li><a class="dropdown-item" href="#">Something else here</a></li>
            </ul>
          </li>
        </ul>
        <form class="d-flex mt-3" role="search">
          <input class="form-control me-2" type="search" placeholder="Search" aria-label="Search">
          <button class="btn btn-outline-success" type="submit">Search</button>
        </form>
      </div>
    </div>
  </div>
</nav>

要创建在特定断点（如 ）处扩展为普通导航栏的 offcanvas 导航栏lg，请使用.navbar-expand-lg。

<nav class="navbar navbar-expand-lg bg-body-tertiary fixed-top">
  <a class="navbar-brand" href="#">Offcanvas navbar</a>
  <button class="navbar-toggler" type="button" data-bs-toggle="offcanvas" data-bs-target="#navbarOffcanvasLg" aria-controls="navbarOffcanvasLg">
    <span class="navbar-toggler-icon"></span>
  </button>
  <div class="offcanvas offcanvas-end" tabindex="-1" id="navbarOffcanvasLg" aria-labelledby="navbarOffcanvasLgLabel">
    ...
  </div>
</nav>

在深色导航栏中使用 offcanvas 时，请注意您可能需要在 offcanvas 内容上设置深色背景以避免文本变得难以辨认。在下面的示例中，我们将.navbar-darkand添加.bg-dark到.navbar、.text-bg-darkto the .offcanvas、.dropdown-menu-darkto.dropdown-menu和.btn-close-whiteto.btn-close以使用深色画布进行适当的样式设置。

HTML代码 
<nav class="navbar navbar-dark bg-dark fixed-top">
  <div class="container-fluid">
    <a class="navbar-brand" href="#">Offcanvas dark navbar</a>
    <button class="navbar-toggler" type="button" data-bs-toggle="offcanvas" data-bs-target="#offcanvasDarkNavbar" aria-controls="offcanvasDarkNavbar">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="offcanvas offcanvas-end text-bg-dark" tabindex="-1" id="offcanvasDarkNavbar" aria-labelledby="offcanvasDarkNavbarLabel">
      <div class="offcanvas-header">
        <h5 class="offcanvas-title" id="offcanvasDarkNavbarLabel">Dark offcanvas</h5>
        <button type="button" class="btn-close btn-close-white" data-bs-dismiss="offcanvas" aria-label="Close"></button>
      </div>
      <div class="offcanvas-body">
        <ul class="navbar-nav justify-content-end flex-grow-1 pe-3">
          <li class="nav-item">
            <a class="nav-link active" aria-current="page" href="#">Home</a>
          </li>
          <li class="nav-item">
            <a class="nav-link" href="#">Link</a>
          </li>
          <li class="nav-item dropdown">
            <a class="nav-link dropdown-toggle" href="#" role="button" data-bs-toggle="dropdown" aria-expanded="false">
              Dropdown
            </a>
            <ul class="dropdown-menu dropdown-menu-dark">
              <li><a class="dropdown-item" href="#">Action</a></li>
              <li><a class="dropdown-item" href="#">Another action</a></li>
              <li>
                <hr class="dropdown-divider">
              </li>
              <li><a class="dropdown-item" href="#">Something else here</a></li>
            </ul>
          </li>
        </ul>
        <form class="d-flex mt-3" role="search">
          <input class="form-control me-2" type="search" placeholder="Search" aria-label="Search">
          <button class="btn btn-success" type="submit">Search</button>
        </form>
      </div>
    </div>
  </div>
</nav>

CSS

变量

添加于 v5.2.0

作为 Bootstrap 不断发展的 CSS 变量方法的一部分，导航栏现在使用本地 CSS 变量.navbar来增强实时定制。CSS 变量的值是通过 Sass 设置的，因此仍然支持 Sass 自定义。

  --#{$prefix}navbar-padding-x: #{if($navbar-padding-x == null, 0, $navbar-padding-x)};
  --#{$prefix}navbar-padding-y: #{$navbar-padding-y};
  --#{$prefix}navbar-color: #{$navbar-light-color};
  --#{$prefix}navbar-hover-color: #{$navbar-light-hover-color};
  --#{$prefix}navbar-disabled-color: #{$navbar-light-disabled-color};
  --#{$prefix}navbar-active-color: #{$navbar-light-active-color};
  --#{$prefix}navbar-brand-padding-y: #{$navbar-brand-padding-y};
  --#{$prefix}navbar-brand-margin-end: #{$navbar-brand-margin-end};
  --#{$prefix}navbar-brand-font-size: #{$navbar-brand-font-size};
  --#{$prefix}navbar-brand-color: #{$navbar-light-brand-color};
  --#{$prefix}navbar-brand-hover-color: #{$navbar-light-brand-hover-color};
  --#{$prefix}navbar-nav-link-padding-x: #{$navbar-nav-link-padding-x};
  --#{$prefix}navbar-toggler-padding-y: #{$navbar-toggler-padding-y};
  --#{$prefix}navbar-toggler-padding-x: #{$navbar-toggler-padding-x};
  --#{$prefix}navbar-toggler-font-size: #{$navbar-toggler-font-size};
  --#{$prefix}navbar-toggler-icon-bg: #{escape-svg($navbar-light-toggler-icon-bg)};
  --#{$prefix}navbar-toggler-border-color: #{$navbar-light-toggler-border-color};
  --#{$prefix}navbar-toggler-border-radius: #{$navbar-toggler-border-radius};
  --#{$prefix}navbar-toggler-focus-width: #{$navbar-toggler-focus-width};
  --#{$prefix}navbar-toggler-transition: #{$navbar-toggler-transition};

一些额外的 CSS 变量也存在于.navbar-nav：

  --#{$prefix}nav-link-padding-x: 0;
  --#{$prefix}nav-link-padding-y: #{$nav-link-padding-y};
  @include rfs($nav-link-font-size, --#{$prefix}nav-link-font-size);
  --#{$prefix}nav-link-font-weight: #{$nav-link-font-weight};
  --#{$prefix}nav-link-color: var(--#{$prefix}navbar-color);
  --#{$prefix}nav-link-hover-color: var(--#{$prefix}navbar-hover-color);
  --#{$prefix}nav-link-disabled-color: var(--#{$prefix}navbar-disabled-color);

通过 CSS 变量进行自定义可以在.navbar-dark类上看到，我们在其中覆盖特定值而不添加重复的 CSS 选择器。

  --#{$prefix}navbar-color: #{$navbar-dark-color};
  --#{$prefix}navbar-hover-color: #{$navbar-dark-hover-color};
  --#{$prefix}navbar-disabled-color: #{$navbar-dark-disabled-color};
  --#{$prefix}navbar-active-color: #{$navbar-dark-active-color};
  --#{$prefix}navbar-brand-color: #{$navbar-dark-brand-color};
  --#{$prefix}navbar-brand-hover-color: #{$navbar-dark-brand-hover-color};
  --#{$prefix}navbar-toggler-border-color: #{$navbar-dark-toggler-border-color};
  --#{$prefix}navbar-toggler-icon-bg: #{escape-svg($navbar-dark-toggler-icon-bg)};

Sass 变量

所有导航栏的变量：

$navbar-padding-y:                  $spacer * .5;
$navbar-padding-x:                  null;

$navbar-nav-link-padding-x:         .5rem;

$navbar-brand-font-size:            $font-size-lg;
// Compute the navbar-brand padding-y so the navbar-brand will have the same height as navbar-text and nav-link
$nav-link-height:                   $font-size-base * $line-height-base + $nav-link-padding-y * 2;
$navbar-brand-height:               $navbar-brand-font-size * $line-height-base;
$navbar-brand-padding-y:            ($nav-link-height - $navbar-brand-height) * .5;
$navbar-brand-margin-end:           1rem;

$navbar-toggler-padding-y:          .25rem;
$navbar-toggler-padding-x:          .75rem;
$navbar-toggler-font-size:          $font-size-lg;
$navbar-toggler-border-radius:      $btn-border-radius;
$navbar-toggler-focus-width:        $btn-focus-width;
$navbar-toggler-transition:         box-shadow .15s ease-in-out;

$navbar-light-color:                rgba(var(--#{$prefix}emphasis-color-rgb), .65);
$navbar-light-hover-color:          rgba(var(--#{$prefix}emphasis-color-rgb), .8);
$navbar-light-active-color:         rgba(var(--#{$prefix}emphasis-color-rgb), 1);
$navbar-light-disabled-color:       rgba(var(--#{$prefix}emphasis-color-rgb), .3);
$navbar-light-toggler-icon-bg:      url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'><path stroke='#{rgba($body-color, .75)}' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/></svg>");
$navbar-light-toggler-border-color: rgba(var(--#{$prefix}emphasis-color-rgb), .15);
$navbar-light-brand-color:          $navbar-light-active-color;
$navbar-light-brand-hover-color:    $navbar-light-active-color;

深色导航栏的变量：

$navbar-dark-color:                 rgba($white, .55);
$navbar-dark-hover-color:           rgba($white, .75);
$navbar-dark-active-color:          $white;
$navbar-dark-disabled-color:        rgba($white, .25);
$navbar-dark-toggler-icon-bg:       url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'><path stroke='#{$navbar-dark-color}' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/></svg>");
$navbar-dark-toggler-border-color:  rgba($white, .1);
$navbar-dark-brand-color:           $navbar-dark-active-color;
$navbar-dark-brand-hover-color:     $navbar-dark-active-color;

Sass循环

响应式导航栏展开/折叠类（例如，.navbar-expand-lg）与$breakpoints地图结合并通过循环生成scss/_navbar.scss。

// Generate series of `.navbar-expand-*` responsive classes for configuring
// where your navbar collapses.
.navbar-expand {
  @each $breakpoint in map-keys($grid-breakpoints) {
    $next: breakpoint-next($breakpoint, $grid-breakpoints);
    $infix: breakpoint-infix($next, $grid-breakpoints);

    // stylelint-disable-next-line scss/selector-no-union-class-name
    &#{$infix} {
      @include media-breakpoint-up($next) {
        flex-wrap: nowrap;
        justify-content: flex-start;

        .navbar-nav {
          flex-direction: row;

          .dropdown-menu {
            position: absolute;
          }

          .nav-link {
            padding-right: var(--#{$prefix}navbar-nav-link-padding-x);
            padding-left: var(--#{$prefix}navbar-nav-link-padding-x);
          }
        }

        .navbar-nav-scroll {
          overflow: visible;
        }

        .navbar-collapse {
          display: flex !important; // stylelint-disable-line declaration-no-important
          flex-basis: auto;
        }

        .navbar-toggler {
          display: none;
        }

        .offcanvas {
          // stylelint-disable declaration-no-important
          position: static;
          z-index: auto;
          flex-grow: 1;
          width: auto !important;
          height: auto !important;
          visibility: visible !important;
          background-color: transparent !important;
          border: 0 !important;
          transform: none !important;
          @include box-shadow(none);
          @include transition(none);
          // stylelint-enable declaration-no-important

          .offcanvas-header {
            display: none;
          }

          .offcanvas-body {
            display: flex;
            flex-grow: 0;
            padding: 0;
            overflow-y: visible;
          }
        }
      }
    }
  }
}