Bootstrap Dropdown 使下拉箭头改变方向

Question

我正在寻找一种方法，使引导下拉菜单箭头在菜单关闭时改变方向，在菜单打开时改变方向。

这是我的html代码：

<!-- Navigation -->
<nav class="navbar navbar-trans navbar-fixed-top" role="navigation">
  <!-- Container makes the navbar extend across the whole screen, removing the default curved sides -->
  <div class="container">
  <!-- Brand and toggle get grouped for better mobile display -->
    <div class="navbar-header">
      <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="#">Project Pandora</a>
    </div>
<!-- Collect the nav links, forms, and other content for toggling -->
  <div class="collapse navbar-collapse" id="navbar-collapse-1">
    <ul class="nav navbar-nav">
    </ul>
    <ul class="nav navbar-nav navbar-right">
      <% if defined?(Devise) %>
        <% if user_signed_in? %>
          <li class="dropdown">
            <a href="#" class="dropdown-toggle" data-toggle="dropdown">Account <b class="caret"></b></a>
            <ul class="dropdown-menu">
              <li><%= link_to "Edit Account", edit_user_registration_path %></li>
              <li><a href="#">Do Something</a></li>
              <li class="divider"></li>
              <li><%= link_to "Sign Out", destroy_user_session_path, method: :delete %></li>
            </ul>
          </li>
        <% else %>
          <li><%= link_to "Login", new_user_session_path %></li>
          <li><%= link_to "Sign Up", new_user_registration_path %></li>
        <% end %>
      <% end %>
    </ul>
  </div><!-- /.navbar-collapse -->
  </div><!-- container-collapse -->
</nav>

我认为在 js 中最容易做到。

这是我的 jsfiddle 代码：https://jsfiddle.net/Pabi/RxguB/75/

谢谢。

Answer 1

试试这个代码。

<!-- Navigation -->
<nav class="navbar navbar-trans navbar-fixed-top" role="navigation">
  <!-- Container makes the navbar extend across the whole screen, removing the default curved sides -->
  <div class="container">
  <!-- Brand and toggle get grouped for better mobile display -->
    <div class="navbar-header">
      <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="#">Project Pandora</a>
    </div>
<!-- Collect the nav links, forms, and other content for toggling -->
  <div class="collapse navbar-collapse" id="navbar-collapse-1">
    <ul class="nav navbar-nav">
    </ul>
    <ul class="nav navbar-nav navbar-right">
          <li class="dropdown">
            <a href="#" class="dropdown-toggle" data-toggle="dropdown">Account <b class='caret' id='menu-caret'></b></a>
            <ul class="dropdown-menu">
              <li><%= link_to "Edit Account", edit_user_registration_path %></li>
              <li><a href="#">Do Something</a></li>
              <li class="divider"></li>
              <li><a href="/signout">Sign Out</a></li>
            </ul>
          </li>
    </ul>
  </div><!-- /.navbar-collapse -->
  </div><!-- container-collapse -->
</nav>

并添加脚本

<script>  
    $('ul.nav li.dropdown').hover(function() {
      $(this).find('.dropdown-menu').stop(true, true).delay(0).fadeIn();
      $('#menu-caret').addClass('glyphicon glyphicon-chevron-up');
      $('#menu-caret').removeClass('caret');
    }, function() {
      $(this).find('.dropdown-menu').stop(true, true).delay(0).fadeOut();
      $('#menu-caret').addClass('caret');
      $('#menu-caret').removeClass('glyphicon glyphicon-chevron-up');
    }); 
</script>

删除你的 CSS 中的 onhover css

请参考这个小提琴http://jsfiddle.net/7o8sLhgf/