Bootstrap - 在导航栏中输入跨越多列

Bootstrap - input in navbar spanning several columns

在 Bootstrap 3.3.4 中,我尝试在品牌名称旁边的导航栏中设置一个输入组,该输入组跨越 8 个中央列。不幸的是,输入组要么似乎保持固定大小,要么延伸输入组插件。最接近我想要实现的代码(模这个拉伸)是这样的:

<nav class="navbar navbar-default" role="navigation">
  <div class="container-fluid">
    <div class="row">
    <div class="col-xs-2">
      <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#navbar-collapsible">
        <span class="sr-only">Toggle navigation</span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <a class="navbar-brand" href="#">Brand</a>
    </div>

    <div class="col-xs-8">
      <form class="navbar-form">
        <div class="form-group" style="width: 100%">
          <div class="input-group" style="width: 100%">
            <input type="text" class="form-control"  style="width: 100%">
            <span class="input-group-addon">
              <span class="glyphicon glyphicon-search"></span>
            </span>
          </div>
        </div>
      </form>
    </div>
  </div>

如果您给表单一个 class 的表单,它将允许表单组根据需要拉伸到 100%。

 <nav class="navbar navbar-default" role="navigation">
  <div class="container-fluid">
    <div class="row">
    <div class="col-xs-2">
      <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#navbar-collapsible">
        <span class="sr-only">Toggle navigation</span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <a class="navbar-brand" href="#">Brand</a>
    </div>

    <div class="col-xs-8">
      <form class="form">
        <div class="form-group">
          <div class="input-group" style="">
            <input type="text" class="form-control">
            <span class="input-group-addon">
              <span class="glyphicon glyphicon-search"></span>
            </span>
          </div>
        </div>
      </form>
    </div>
  </div>
 </nav>

http://codepen.io/anon/pen/QbWMax