html - 使导航折叠

Question

这是来自 Bootstrap 网站的导航栏，以及 css。我怎样才能让它在低于 768px 时折叠？我想要一个合理的导航并尝试查看具有折叠功能的导航，但不确定在哪里添加它。任何帮助，将不胜感激。谢谢，jodmcc

HTML

  <!-- The justified navigation menu is meant for single line per list item.
       Multiple lines will require custom code not provided by Bootstrap. -->
  <div class="masthead">
    <h3 class="text-muted">Project name</h3>
    <nav>
      <ul class="nav nav-justified">
        <li class="active"><a href="#">Home</a></li>
        <li><a href="#">Projects</a></li>
        <li><a href="#">Services</a></li>
        <li><a href="#">Downloads</a></li>
        <li><a href="#">About</a></li>
        <li><a href="#">Contact</a></li>
      </ul>
    </nav>
  </div>

CSS

   .nav-justified {
  background-color: #eee;
  border: 1px solid #ccc;
  border-radius: 5px;
}
.nav-justified > li > a {
  padding-top: 15px;
  padding-bottom: 15px;
  margin-bottom: 0;
  font-weight: bold;
  color: #777;
  text-align: center;
  background-color: #e5e5e5; /* Old browsers */
  background-image: -webkit-gradient(linear, left top, left     bottom,     from(#f5f5f5), to(#e5e5e5));
  background-image: -webkit-linear-gradient(top, #f5f5f5 0%, #e5e5e5     100%);
  background-image:      -o-linear-gradient(top, #f5f5f5 0%, #e5e5e5     100%);
  background-image:         linear-gradient(to bottom, #f5f5f5     0%,#e5e5e5 100%);
  filter: progid:DXImageTransform.Microsoft.gradient(         startColorstr='#f5f5f5', endColorstr='#e5e5e5',GradientType=0 ); /* IE6-9 */
  background-repeat: repeat-x; /* Repeat the gradient */
  border-bottom: 1px solid #d5d5d5;
    }
    .nav-justified > .active > a,
    .nav-justified > .active > a:hover,
    .nav-justified > .active > a:focus {
      background-color: #ddd;
      background-image: none;
      -webkit-box-shadow: inset 0 3px 7px rgba(0,0,0,.15);
          box-shadow: inset 0 3px 7px rgba(0,0,0,.15);
    }
    .nav-justified > li:first-child > a {
      border-radius: 5px 5px 0 0;
    }
    .nav-justified > li:last-child > a {
      border-bottom: 0;
      border-radius: 0 0 5px 5px;
    }

Answer 1

您可以在应隐藏在 768px 以下的元素上使用 Bootstrap 的 .hidden-xs CSS 类。相反，您可以使用 .visible-xs-block、.visible-xs-inline 或 .visible-xs 使元素仅出现在 768px 或更高像素以上-inline-block(取决于您的显示样式)。

例如，您可以尝试:

<div class="hidden-xs">
    Standard menu code, visible at 768px or above
</div>
<div class="visible-xs-block">
    Collapsed menu code, only visible below 768px
</div>