html - CSS Bootstrap navbar- 中心搜索栏，在折叠时占据整个宽度

Question

我有一个包含 3 个元素的 Bootstrap v.3 导航栏。我想均匀对齐元素，以便搜索栏在导航栏中居中。当它折叠时，它会占据整个宽度。但是很难做到这一点。

这是它的 html:

      <nav class="navbar navbar-transparent navbar-fixed-top" role="navigation">

        <div class="container">
          <!-- Brand and toggle get grouped for better mobile display -->
          <div class="col-lg-4 navbar-header">
            <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1">
              <span class="sr-only">Toggle navigation</span>
              <span class="icon-bar"></span>
              <span class="icon-bar"></span>
              <span class="icon-bar"></span>
            </button>
            <img src="assets/img/logo.png" alt="logo">
          </div>

          <!-- Collect the nav links, forms, and other content for toggling -->
          <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
            <form class="navbar-form navbar-left navbar-search-form active" role="search">
               <div class="form-group">
                  <input type="text" value="" class="form-control" placeholder="Search...">
               </div>
            </form>
                    <ul class="nav navbar-nav">
              <li class="active">
                  <a href="javascript:void(0);"><i class="fa fa-search"></i></a>
              </li>
            </ul>
            <ul class="nav navbar-nav navbar-right">
              <li><button href="#gsdk" class="btn btn-round btn-default">Sign in</button></li>
            </ul>

          </div><!-- /.navbar-collapse -->
        </div><!-- /.container-fluid -->
      </nav>

我试图制作一个 fiddle对于它，但结果并不好，但希望那里的代码可以提供一些想法。

Answer 1

最简单的方法是使用flex，但是浏览器兼容性差，所以可以使用media queries和position:absolute; .navbar-form.

将 position-relative 赋予 nav 内的 div .container。我给了它一些边界，所以你可以看到居中。您的 sign in 按钮一直停留在右上角，因为您已经为它指定了 navbar-right 类。

.navbar-header img{
  width:70px;
  margin:0;
}
.navbar-container{
  position:relative;
  border:1px solid red;
}
.navbar-header button span{
  color:black;
  background-color:green;
}
@media screen and (min-width:768px){
  form.navbar-form{
    position:absolute;
    top:50%;
    left:50%;
    transform:translate(-50%,-50%);
    margin:0;
  }
}

<link href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css" rel="stylesheet"/>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/js/bootstrap.min.js"></script>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>

<nav class="navbar navbar-transparent navbar-fixed-top" role="navigation">
  <div class="container navbar-container">
    <div class="navbar-header">
      <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1">
        <span class="sr-only">Toggle navigation</span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <img src="http://www.chinabuddhismencyclopedia.com/en/images/thumb/b/b8/Nature.jpg/240px-Nature.jpg" alt="logo">
    </div>
   <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
      <form class="navbar-form navbar-search-form active" role="search">
        <div class="form-group">
          <input type="text" value="" class="form-control" placeholder="Search...">
          <a href="javascript:void(0);"><i class="fa fa-search"></i></a>
        </div>
      </form>
      <ul class="nav navbar-nav navbar-right">
         <li><button href="#gsdk" class="btn btn-round btn-default">Sign in</button></li>
      </ul>
    </div><!-- /.navbar-collapse -->
  </div><!-- /.container-fluid -->
</nav>