详解bootstrap导航栏.nav与.navbar区别

2019-11-19 14:52:16

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刚刚看了bootstrap的导航栏，发现有点弄混了，现在来整理一下；

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。

一、简单的ul,li组成的导航：

<ul class="nav nav-pills justify-content-center bg-dark nav-dark">    <li class="nav-item">      <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="nav-link">1</a>    </li>    <li class="nav-item">      <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="nav-link">2</a>    </li>    <li class="nav-item">      <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="nav-link">3</a>    </li>  </ul> //解析：.nav .nav-item .nav-link表示ul li是导航――.nav-pills表示胶囊状导航――.bg-dark/.nav-dark表示黑底白字――.justify-content-center表示导航栏在浏览器上居中显示

在浏览器上显示为：

缩小浏览器窗口显示为：

二、导航栏――<nav>标签中class="navbar navbar-expand-sm"――<ul>中class="navbar-nav"――<li>中class="nav-item"

代码为：

<nav class="navbar navbar-expand-sm bg-dark navbar-dark">  <ul class="navbar-nav">    <li class="nav-item active">      <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="nav-link">link1</a>    </li>    <li class="nav-item">      <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="nav-link">link1</a>    </li>    <li class="nav-item">      <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="nav-link">link1</a>    </li>    <li class="nav-item">      <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="nav-link">link1</a>    </li>    </ul></nav>

正常窗口显示为：

缩小窗口小于576px时：

三、折叠导航栏

当窗口小于576px的时候，不仅仅是简单的编程垂直导航；显示为一个button按钮，导航链接隐藏，点击button显示；

代码为：

<nav class="navbar navbar-expand-sm bg-dark navbar-dark fixed-top">  <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="navbar-brand">      <img src="" alt="logo" style="width:70px;height:30px;">  </a>  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#collapsible">    <span class="navbar-toggler-icon"></span>  </button>  <div class="collapse navbar-collapse" id="collapsible">  <ul class="navbar-nav">    <li class="nav-item active">      <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="nav-link">link1</a>    </li>    <li class="nav-item">      <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="nav-link">link1</a>    </li>    <li class="nav-item">      <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="nav-link">link1</a>    </li>    <li class="nav-item">      <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="nav-link">link1</a>    </li>    </ul>  </nav>

//注意：.navbar-brand是品牌logo；

窗口大于576的时候，显示为：

窗口小于576的时候，显示为：

四、导航栏加上form表单表示搜索框：【？？？？？】

代码如下：

<nav class="navbar navbar-expand-sm bg-dark navbar-dark fixed-top">  <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="navbar-brand">      <img src="" alt="logo" style="width:70px;height:30px;">  </a>  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#collapsible">    <span class="navbar-toggler-icon"></span>  </button>  <div class="collapse navbar-collapse" id="collapsible">  <ul class="navbar-nav">    <li class="nav-item active">      <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="nav-link">link1</a>    </li>    <li class="nav-item">      <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="nav-link">link1</a>    </li>    <li class="nav-item">      <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="nav-link">link1</a>    </li>    <li class="nav-item">      <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="nav-link">link1</a>    </li>    </ul>  <form class="form-inline">        <div class="input-group">          <span class="input-group-addon">@</span>          <input list="dl" type="text" class="form-control" placeholder="Search"/>          <datalist id="dl">            <option value="IE"></option>            <option value="Firefox"></option>            <option value="chrome"></option>            <option value="safari"></option>          </datalist>        </div>                <button class="btn btn-success" type="submit">search</button>      </form></nav>

如图所示，如何使得导航栏中的form表单右对齐，移到最右边？？？？？float：eight应该也行吧。。

emmmm.....知道了上面的解决方法了：利用网格系统，将左边的ul,li和右边的form表单分别排列；.col-sm-6;然后再给form表单右浮动；

代码如下：

<div class="container-fluid">  <div class="row">    <!-- 导航栏 -->    <nav class="navbar fixed-top navbar-expand-sm bg-dark navbar-dark">      <div class="col-lg-4">      <ul class="navbar-nav">        <li class="nav-item">          <a class="nav-link" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >link1</a>        </li>        <li class="nav-item">          <a class="nav-link" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >link2</a>        </li>        <li class="nav-item">          <a class="nav-link" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >link3</a>        </li>      </ul>      </div><!-- 导航栏表单与按钮 -->    <div class="col-lg-8">      <form class="form-inline" style="float:right;">        <div class="input-group">          <span class="input-group-addon">@</span>          <input list="dl" type="text" class="form-control" placeholder="Search"/>          <datalist id="dl">            <option value="IE"></option>            <option value="Firefox"></option>            <option value="chrome"></option>            <option value="safari"></option>          </datalist>          <button class="btn btn-success" type="submit">search</button>        </div>                    </form>      </div>          </nav>    </div>      </div>