Bootstrap 导航栏
导航栏是一个很好的功能，是 Bootstrap 网站的一个突出特点。导航栏在您的应用或网站中作为导航页头的响应式基础组件。导航栏在移动设备的视图中是折叠的，随着可用视口宽度的增加，导航栏也会水平展开。在 Bootstrap 导航栏的核心中，导航栏包括了站点名称和基本的导航定义样式。
默认的导航栏
创建一个默认的导航栏的步骤如下：
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向 <nav> 标签 添加 class .navbar、.navbar-default。
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向上面的元素添加 role="navigation"，有助于增加可访问性。
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向 <div> 元素添加一个标题 class .navbar-header，内部包含了带有 class navbar-brand 的 <a> 元素。这会让文本看起来更大一号。
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为了向导航栏添加链接，只需要简单地添加带有 class .nav、.navbar-nav 的无序列表即可。
下面的实例演示了这点：
-------------------------------------------------- --------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -------------------------------------------------------- ------------------------------------------------------------------------------------------------------ ------------------------------ ----------------------------- ------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------------------------------------------------ --------------------------------------------------------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------------------------------------------ ----------------------------------------------------------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------------------------------ -------------------------------------------------------------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------- ----------------------------------------------------------------- ----------------------------------------------- --------------------------------------------------------------------
结果如下所示：
响应式的导航栏
为了给导航栏添加响应式特性，您要折叠的内容必须包裹在带有 classes .collapse、.navbar-collapse 的 <div> 中。折叠起来的导航栏实际上是一个带有 class .navbar-toggle 及两个 data- 元素的按钮。第一个是 data-toggle，用于告诉 JavaScript 需要对按钮做什么，第二个是 data-target，指示要切换到哪一个元素。三个带有 class .icon-bar 的 <span> 创建所谓的汉堡按钮。这些会切换为 .nav-collapse <div> 中的元素。为了实现以上这些功能，您必须包含 Bootstrap 折叠（Collapse）插件。
下面的实例演示了这点：
-------------------------------------------------- ---------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -------------------------------------------------------- ------------------------------------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------ -------------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------- --------------------------------------------------- ------------------------------------------------------------------------------------------------------ ------------------------------ ---------------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------------------------------------ ---------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------------------------------------------------ --------------------------------------------------------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------------------------------------------ ----------------------------------------------------------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------------------------------ -------------------------------------------------------------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------- ----------------------------------------------------------------- ----------------------------------------------- --------------------------------------------------------------------
结果如下所示：
