Bootstrap导航栏在悬停时不显示下拉菜单

Question

我正在使用bootstrap的导航栏，并且遇到一个问题，当链接之一是下拉菜单时，菜单不显示。

看一下开发工具，我发现显示没有从无到有变化。

谁能解释这里可能是什么问题？ 是的，bootstrap的css和js包含在我的项目中。

HTML

<div class="navbar navbar-default" id="div-nav-bar">
    <div class="container-fluid">
        <div class="navbar-header">
            <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#nav-collapse" aria-expanded="false" (click)="showHide()">
                <span class="sr-only">Toggle navigation</span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
            </button>
            <div class="navbar-brand">
                <img src="../assets/images/logo_small.png" alt="IRIS Logo" />
            </div>
        </div>
        <div class="collapse navbar-collapse" id="nav-collapse">
            <ul class="nav navbar-nav">
                <li class="dropdown">
                    <a class="dropdown-toggle" data-toggle="dropdown">
                        <i class="glyphicon glyphicon-dashboard"></i>
                        <span>Dashboards </span>
                        <span class="caret"></span>
                    </a>
                    <ul class="dropdown-menu">
                        <li>
                            <a href="dashboard">
                                <i class="glyphicon glyphicon-facetime-video"></i>
                                <span>Fundus Exams</span>
                            </a>
                        </li>
                        <li>
                            <a href="glaucoma">
                                <i class="glyphicon glyphicon-camera"></i>
                                <span>Glaucoma Exams</span>
                            </a>
                        </li>
                    </ul>
                </li>
                <li class="dropdown">
                    <a href="#" class="dropdown-toggle" data-toggle="dropdown">
                        <i class="glyphicon glyphicon-list-alt"></i>
                        <span>Reporting </span>
                        <span class="caret"></span>
                    </a>
                    <ul class="dropdown-menu">
                        <li>
                            <a href="#">
                                <i class="glyphicon glyphicon-folder-open"></i>
                                <span>Results</span>
                            </a>
                        </li>
                        <li class="active">
                            <a href="#">
                                <i class="glyphicon glyphicon-tasks"></i>
                                <span>Patient Result Report</span>
                            </a>
                        </li>
                    </ul>
                </li>
            </ul>
            <ul class="nav navbar-nav navbar-right">
                <li>
                    <a href="grading" class="start-grading">
                        <i class="glyphicon glyphicon-sunglasses"></i>
                        <span>Start Grading</span>
                    </a>
                </li>
                <li role="separator" class="divider">&nbsp;</li>
                <li>
                    <a href="#" class="logout">
                        <i class="glyphicon glyphicon-log-out"></i>
                        <span>Logout</span>
                    </a>
                </li>
            </ul>
        </div>
    </div>
</div>

Answer 1

在JQuery代码下面添加hover和mouseleave将在hover上显示下拉菜单。

请参见下面的代码段：

 $(function() { $(".navbar li.dropdown").hover(function(e) { $(this).addClass("open"); }); $(".navbar li.dropdown").mouseleave(function() { $(this).removeClass("open"); }); }); 

 /*.dropdown-menu li:hover .sub-menu { visibility: visible; } .dropdown:hover .dropdown-menu { display: block; } */ .dropdown:hover ul.dropdown-menu { animation-name: fadeInLeft; animation-fill-mode: both; animation-timing-function: ease-out; animation-duration: 0.2s; animation-delay: 0s; } @keyframes fadeInLeft { from { visibility: hidden; opacity: 0; transform: scale(0) translateX(0); } to { visibility: visible; opacity: 1; transform: scale(1) translateX(-25px); } } 

 <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://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" /> <div class="navbar navbar-default" id="div-nav-bar"> <div class="container-fluid"> <div class="navbar-header"> <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#nav-collapse" aria-expanded="false" (click)="showHide()"> <span class="sr-only">Toggle navigation</span> <span class="icon-bar"></span> <span class="icon-bar"></span> <span class="icon-bar"></span> </button> <div class="navbar-brand"> <img src="../assets/images/logo_small.png" alt="IRIS Logo" /> </div> </div> <div class="collapse navbar-collapse" id="nav-collapse"> <ul class="nav navbar-nav"> <li class="dropdown"> <a class="dropdown-toggle" data-toggle="dropdown"> <i class="glyphicon glyphicon-dashboard"></i> <span>Dashboards </span> <span class="caret"></span> </a> <ul class="dropdown-menu"> <li> <a href="dashboard"> <i class="glyphicon glyphicon-facetime-video"></i> <span>Fundus Exams</span> </a> </li> <li> <a href="glaucoma"> <i class="glyphicon glyphicon-camera"></i> <span>Glaucoma Exams</span> </a> </li> </ul> </li> <li class="dropdown"> <a href="#" class="dropdown-toggle" data-toggle="dropdown"> <i class="glyphicon glyphicon-list-alt"></i> <span>Reporting </span> <span class="caret"></span> </a> <ul class="dropdown-menu"> <li> <a href="#"> <i class="glyphicon glyphicon-folder-open"></i> <span>Results</span> </a> </li> <li class="active"> <a href="#"> <i class="glyphicon glyphicon-tasks"></i> <span>Patient Result Report</span> </a> </li> </ul> </li> </ul> <ul class="nav navbar-nav navbar-right"> <li> <a href="grading" class="start-grading"> <i class="glyphicon glyphicon-sunglasses"></i> <span>Start Grading</span> </a> </li> <li role="separator" class="divider">&nbsp;</li> <li> <a href="#" class="logout"> <i class="glyphicon glyphicon-log-out"></i> <span>Logout</span> </a> </li> </ul> </div> </div> </div>