这里是JSFiddle -> https://jsfiddle.net/PRkonsult/mn31qf0p/1/

底部的JavaScript部分是真正起作用的部分。

HTML

<!--http://getbootstrap.com/components/#navbar-->
<div class="body-wrap">
  <div class="container">
    <nav class="navbar navbar-inverse" role="navigation">
      <div class="container-fluid">
        <!-- Brand and toggle get grouped for better mobile display -->
        <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>
          <a class="navbar-brand" href="#">Brand</a>
        </div>

        <!-- Collect the nav links, forms, and other content for toggling -->
        <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
          <ul class="nav navbar-nav">
            <li class="active"><a href="#">Link</a></li>
            <li><a href="#">Link</a></li>
            <li class="dropdown">
              <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown <b class="caret"></b></a>
              <ul class="dropdown-menu">
                <li><a href="#">Action</a></li>
                <li><a href="#">Another action</a></li>
                <li><a href="#">Something else here</a></li>
                <li class="divider"></li>
                <li><a href="#">Separated link</a></li>
                <li class="divider"></li>
                <li><a href="#">One more separated link</a></li>
              </ul>
            </li>
          </ul>

          <ul class="nav navbar-nav navbar-right">
            <li><a href="#">Link</a></li>
            <li class="dropdown">
              <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown <b class="caret"></b></a>
              <ul class="dropdown-menu">
                <li><a href="#">Action</a></li>
                <li><a href="#">Another action</a></li>
                <li><a href="#">Something else here</a></li>
                <li class="divider"></li>
                <li><a href="#">Separated link</a></li>
              </ul>
            </li>
          </ul>
        </div>
        <!-- /.navbar-collapse -->
      </div>
      <!-- /.container-fluid -->
    </nav>
  </div>
</div>

CSS

/* Bootstrap dropdown hover menu */

body {
  font-family: 'PT Sans', sans-serif;
  font-size: 13px;
  font-weight: 400;
  color: #4f5d6e;
  position: relative;
  background: rgb(26, 49, 95);
  background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, rgba(26, 49, 95, 1)), color-stop(10%, rgba(26, 49, 95, 1)), color-stop(24%, rgba(29, 108, 141, 1)), color-stop(37%, rgba(41, 136, 151, 1)), color-stop(77%, rgba(39, 45, 100, 1)), color-stop(90%, rgba(26, 49, 95, 1)), color-stop(100%, rgba(26, 49, 95, 1)));
  filter: progid: DXImageTransform.Microsoft.gradient(startColorstr='#1a315f', endColorstr='#1a315f', GradientType=0);
}

.body-wrap {
  min-height: 700px;
}

.body-wrap {
  position: relative;
  z-index: 0;
}

.body-wrap: before,
.body-wrap: after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  z-index: -1;
  height: 260px;
  background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, rgba(26, 49, 95, 1)), color-stop(100%, rgba(26, 49, 95, 0)));
  background: linear-gradient(to bottom, rgba(26, 49, 95, 1) 0%, rgba(26, 49, 95, 0) 100%);
  filter: progid: DXImageTransform.Microsoft.gradient(startColorstr='#1a315f', endColorstr='#001a315f', GradientType=0);
}

.body-wrap:after {
  top: auto;
  bottom: 0;
  background: linear-gradient(to bottom, rgba(26, 49, 95, 0) 0%, rgba(26, 49, 95, 1) 100%);
  filter: progid: DXImageTransform.Microsoft.gradient(startColorstr='#001a315f', endColorstr='#1a315f', GradientType=0);
}

nav {
  margin-top: 60px;
  box-shadow: 5px 4px 5px #000;
}

JavaScript代码的重要部分:

$('ul.nav li.dropdown').hover(function() {
  $(this).find('.dropdown-menu').stop(true, true).delay(200).fadeIn(500);
}, function() {
  $(this).find('.dropdown-menu').stop(true, true).delay(200).fadeOut(500);
});

为了加强Sudharshan的回答，我将其包装在一个媒体查询中，以防止在XS显示宽度上出现悬停……

@media (min-width:768px)
{
    ul.nav li.dropdown:hover > ul.dropdown-menu {
        display: block;    
    }

    .nav .dropdown-menu {
        margin-top: 0;
    }
}

标记中的插入符号也不是必需的，只是li的下拉类。

这将隐藏下拉列表和它们的插入符号，如果它们比平板电脑小。

@media (max-width: 768px) {
    .navbar ul.dropdown-menu, .navbar li.dropdown b.caret {
        display: none;
    }
}

内联使用两个链接。用下拉按钮隐藏链接，并在可见链接上添加onmouseover事件以单击下拉菜单。

<a class="pretty-button"
   href="#" alt="Notifications"
   onmouseover="$('#notifications-dropdown').click()">
</a>

<a style="display:none"
   id="notifications-dropdown"
   class="js-nav js-tooltip js-dynamic-tooltip"
   href="#"
   alt="Notifications"
   data-toggle="dropdown">
   <span class="fa fa-flag fa-2x"></span>
</a>

最标准的回答:

支持aria-expanded属性 支持非触摸设备 支持触摸设备 支持所有下拉菜单

var isTouchDevice = (('ontouchstart' in window) ||
                                (navigator.MaxTouchPoints > 0) ||
                                (navigator.msMaxTouchPoints > 0));
if(!isTouchDevice){
    // open dropdowns on hover on non mobile devices
    $(".dropdown").hover(function(e) {
        $('.dropdown-toggle', this).dropdown("toggle");
        e.stopPropagation();
    });
    // prevent blinkling
    $(".submenu-link").click(function(e) {
        e.stopPropagation();
    });
}

如果你需要，你可以将$(".dropdown")更改为特定的区域:

$("#top-menu .dropdown")

以下是我的技巧，它在你停止在菜单或切换按钮上悬停后，在菜单关闭之前添加了轻微的延迟。你通常点击来显示导航菜单的<按钮>是#nav_dropdown。

$(function() {
  var delay_close_it, nav_menu_timeout, open_it;
  nav_menu_timeout = void 0;
  open_it = function() {
    if (nav_menu_timeout) {
      clearTimeout(nav_menu_timeout);
      nav_menu_timeout = null;
    }
    return $('.navbar .dropdown').addClass('open');
  };
  delay_close_it = function() {
    var close_it;
    close_it = function() {
      return $('.navbar .dropdown').removeClass('open');
    };
    return nav_menu_timeout = setTimeout(close_it, 500);
  };
  $('body').on('mouseover', '#nav_dropdown, #nav_dropdown *', open_it).on('mouseout', '#nav_dropdown', delay_close_it);
  return $('body').on('mouseover', '.navbar .dropdown .dropdown-menu', open_it).on('mouseout', '.navbar .dropdown .dropdown-menu', delay_close_it);
});