Bootstrap 导航栏下拉子菜单在折叠模式下不起作用

Posted 2023-05-08

【中文标题】Bootstrap 导航栏下拉子菜单在折叠模式下不起作用

【英文标题】：Bootstrap navbar dropdown submenu not working in collapsed mode

【发布时间】：2021-01-16 00:50:32

【问题描述】：

我正在建立一个新网站，但我的导航栏卡住了。

我面临的问题是子菜单（第二级下拉菜单）没有以折叠模式显示。如果你按下它像正常的下拉菜单一样打开它，它就好像它本身就是一个链接，而不是打开子菜单。

在全屏模式下，它按预期工作，但在悬停而不是点击时。

.navbar 
  border-top-left-radius: 15px;
  border-bottom-left-radius: 15px;
  border-top-right-radius: 15px;
  border-bottom-right-radius: 15px;
  margin: 20px 50px 20px 50px;


.navbar 
  background-color: #343a40;


.navbar .navbar-brand 
  color: #4d8de5;


.navbar .navbar-brand:hover,
.navbar .navbar-brand:focus 
  color: #1a71e8;


.navbar .navbar-text 
  color: #4d8de5;


.navbar .navbar-text a 
  color: #1a71e8;


.navbar .navbar-text a:hover,
.navbar .navbar-text a:focus 
  color: #1a71e8;


.navbar .navbar-nav .nav-link 
  color: #4d8de5;
  border-radius: .25rem;
  margin: 0 0.25em;


.navbar .navbar-nav .nav-link:not(.disabled):hover,
.navbar .navbar-nav .nav-link:not(.disabled):focus 
  color: #1a71e8;


.navbar .navbar-nav .dropdown-menu 
  background-color: #343a40;
  border: 2px solid #4d535a;


.navbar .navbar-nav .dropdown-menu .dropdown-item 
  color: #4d8de5;


.navbar .navbar-nav .dropdown-menu .dropdown-item:hover,
.navbar .navbar-nav .dropdown-menu .dropdown-item:focus,
.navbar .navbar-nav .dropdown-menu .dropdown-item.active 
  color: #1a71e8;
  background-color: #4d535a;


.navbar .navbar-nav .dropdown-menu .dropdown-divider 
  border-top-color: #4d535a;


.navbar .navbar-nav .nav-item.active .nav-link,
.navbar .navbar-nav .nav-item.active .nav-link:hover,
.navbar .navbar-nav .nav-item.active .nav-link:focus,
.navbar .navbar-nav .nav-item.show .nav-link,
.navbar .navbar-nav .nav-item.show .nav-link:hover,
.navbar .navbar-nav .nav-item.show .nav-link:focus 
  color: #1a71e8;
  background-color: transparent;


.navbar .navbar-toggle 
  border-color: #4d535a;


.navbar .navbar-toggle:hover,
.navbar .navbar-toggle:focus 
  background-color: #4d535a;


.navbar .navbar-toggle .navbar-toggler-icon 
  color: #4d8de5;


.navbar .navbar-collapse,
.navbar .navbar-form 
  border-color: #4d8de5;


.navbar .navbar-link 
  color: #4d8de5;


.navbar .navbar-link:hover 
  color: #1a71e8;


@media (max-width: 575px) 
  .navbar-expand-sm .navbar-nav .show .dropdown-menu .dropdown-item 
    color: #4d8de5;
  
  .navbar-expand-sm .navbar-nav .show .dropdown-menu .dropdown-item:hover,
  .navbar-expand-sm .navbar-nav .show .dropdown-menu .dropdown-item:focus 
    color: #1a71e8;
  
  .navbar-expand-sm .navbar-nav .show .dropdown-menu .dropdown-item.active 
    color: #1a71e8;
    background-color: #4d535a;
  


@media (max-width: 767px) 
  .navbar-expand-md .navbar-nav .show .dropdown-menu .dropdown-item 
    color: #4d8de5;
  
  .navbar-expand-md .navbar-nav .show .dropdown-menu .dropdown-item:hover,
  .navbar-expand-md .navbar-nav .show .dropdown-menu .dropdown-item:focus 
    color: #1a71e8;
  
  .navbar-expand-md .navbar-nav .show .dropdown-menu .dropdown-item.active 
    color: #1a71e8;
    background-color: #4d535a;
  


@media (max-width: 991px) 
  .navbar-expand-lg .navbar-nav .show .dropdown-menu .dropdown-item 
    color: #4d8de5;
  
  .navbar-expand-lg .navbar-nav .show .dropdown-menu .dropdown-item:hover,
  .navbar-expand-lg .navbar-nav .show .dropdown-menu .dropdown-item:focus 
    color: #1a71e8;
  
  .navbar-expand-lg .navbar-nav .show .dropdown-menu .dropdown-item.active 
    color: #1a71e8;
    background-color: #4d535a;
  


@media (max-width: 1199px) 
  .navbar-expand-xl .navbar-nav .show .dropdown-menu .dropdown-item 
    color: #4d8de5;
  
  .navbar-expand-xl .navbar-nav .show .dropdown-menu .dropdown-item:hover,
  .navbar-expand-xl .navbar-nav .show .dropdown-menu .dropdown-item:focus 
    color: #1a71e8;
  
  .navbar-expand-xl .navbar-nav .show .dropdown-menu .dropdown-item.active 
    color: #1a71e8;
    background-color: #4d535a;
  


.navbar-expand .navbar-nav .show .dropdown-menu .dropdown-item 
  color: #4d8de5;


.navbar-expand .navbar-nav .show .dropdown-menu .dropdown-item:hover,
.navbar-expand .navbar-nav .show .dropdown-menu .dropdown-item:focus 
  color: #1a71e8;


.navbar-expand .navbar-nav .show .dropdown-menu .dropdown-item.active 
  color: #1a71e8;
  background-color: #4d535a;


.nav-item.active 
  border-top-left-radius: 5px;
  border-bottom-left-radius: 5px;
  border-top-right-radius: 5px;
  border-bottom-right-radius: 5px;
  border: 2px solid #1a71e8;


.btn-outline-success,
.btn-outline-success:active,
.btn-outline-success:visited 
  background-color: transparent !important;
  border-color: #4d8de5;
  color: #4d8de5;


.btn-outline-success:hover 
  background-color: transparent !important;
  border-color: #1a71e8;
  color: #1a71e8;


.btn-outline-success:focus 
  box-shadow: 0 0 0 .2rem rgb(26, 113, 232)


.btn-outline-success.disabled,
.btn-outline-success:disabled 
  color: #1a71e8;
  background-color: transparent


.btn-outline-success.dropdown-toggle 
  color: #4d8de5;
  background-color: #1a71e8;
  border-color: #1a71e8


.btn-outline-success:not(:disabled):not(.disabled).active:focus,
.btn-outline-success:not(:disabled):not(.disabled):active:focus,
.show>.btn-outline-success.dropdown-toggle:focus 
  box-shadow: 0 0 0 .2rem rgb(26, 113, 232)


@media (min-width: 992px) 
  .dropdown-menu .dropdown-toggle:after 
    border-top: .3em solid transparent;
    border-right: 0;
    border-bottom: .3em solid transparent;
    border-left: .3em solid;
  
  .dropdown-menu .dropdown-menu 
    margin-left: 0;
    margin-right: 0;
  
  .dropdown-menu li 
    position: relative;
  
  .nav-item .submenu 
    display: none;
    position: absolute;
    left: 100%;
    top: -7px;
  
  .nav-item .submenu-left 
    right: 100%;
    left: auto;
  
  .dropdown-menu>li:hover 
    background-color: #f1f1f1
  
  .dropdown-menu>li:hover>.submenu 
    display: block;
  

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
<link rel="stylesheet" type="text/css" href="css/style.css" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"></script>

<div id="page">
  <nav class="navbar navbar-expand-lg navbar-dark bg-dark navbar-custom">
    <a class="navbar-brand" href="#"><img src="images/logo5.png"  style="width: 175px"></a>
    <button class="navbar-toggler collapsed" type="button" data-toggle="collapse" data-target="#navbarsExample09" aria-controls="navbarsExample09" aria-expanded="false" aria-label="Toggle navigation">
            <span class="navbar-toggler-icon"></span>
        </button>
    <div class="navbar-collapse collapse" id="navbarsExample09" style="">
      <ul class="navbar-nav mr-auto">
        <li class="nav-item active">
          <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
        </li>
        <li class="nav-item dropdown">
          <a class="nav-link  dropdown-toggle" href="#" data-toggle="dropdown"> Platform </a>
          <ul class="dropdown-menu dropdown-menu-right">
            <li><a class="dropdown-item" href="#"> Dropdown item 1</a></li>
            <li><a class="dropdown-item" href="#"> Dropdown item 2 </a></li>
            <li><a class="dropdown-item dropdown-toggle" href="#"> Dropdown item 3 </a>
              <ul class="submenu submenu-right dropdown-menu" data-toggle="dropdown">
                <li><a class="dropdown-item" href="">Submenu item 1</a></li>
                <li><a class="dropdown-item" href="">Submenu item 2</a></li>
                <li><a class="dropdown-item" href="">Submenu item 3</a></li>
                <li><a class="dropdown-item" href="">Submenu item 4</a></li>
              </ul>
            </li>
            <li><a class="dropdown-item" href="#"> Dropdown item 4 </a></li>
          </ul>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Add new game</a>
        </li>
      </ul>
      <ul class="navbar-nav ml-auto">
        <form class="form-inline my-2 my-lg-0">
          <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
          <button class="btn btn-outline-success my-2 my-sm-0" style="margin-right: 10px" type="submit">Search</button>
        </form>
        <li class="nav-item dropdown">
          <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                        Account
                    </a>
          <div class="dropdown-menu dropdown-menu-right" aria-labelledby="navbarDropdown">
            <a class="dropdown-item" href="#">Action</a>
            <a class="dropdown-item" href="#">Another action</a>
            <div class="dropdown-divider"></div>
            <a class="dropdown-item" href="#">Something else here</a>
          </div>
        </li>
      </ul>
    </div>
  </nav>
</div>

编辑：我的 javascript 是问题所在。感谢 cmets 中的链接，对我有用的版本如下：

$( document ).ready( function () 
    $( '.dropdown-menu a.dropdown-toggle' ).on( 'click', function ( e ) 
        var $el = $( this );
        var $parent = $( this ).offsetParent( ".dropdown-menu" );
        if ( !$( this ).next().hasClass( 'show' ) ) 
            $( this ).parents( '.dropdown-menu' ).first().find( '.show' ).removeClass( "show" );
        
        var $subMenu = $( this ).next( ".dropdown-menu" );
        $subMenu.toggleClass( 'show' );

        $( this ).parent( "li" ).toggleClass( 'show' );

        $( this ).parents( 'li.nav-item.dropdown.show' ).on( 'hidden.bs.dropdown', function ( e ) 
            $( '.dropdown-menu .show' ).removeClass( "show" );
         );

        if ( !$parent.parent().hasClass( 'navbar-nav' ) ) 
            $el.next().css(  "top": $el[0].offsetTop, "left": $parent.outerWidth() - 4  );
        

        return false;
     );
 );

【参考方案1】：

如果您可以选择 JavaScript 解决方案，我认为 this answer of similar question 可以满足您的需求。

这是未经修改的 JavaScript sn-p：

$('.dropdown-menu a.dropdown-toggle').on('click', function(e) 
  if (!$(this).next().hasClass('show')) 
    $(this).parents('.dropdown-menu').first().find('.show').removeClass('show');
  
  var $subMenu = $(this).next('.dropdown-menu');
  $subMenu.toggleClass('show');


  $(this).parents('li.nav-item.dropdown.show').on('hidden.bs.dropdown', function(e) 
    $('.dropdown-submenu .show').removeClass('show');
  );


  return false;
);

【讨论】：

谢谢！这本身不起作用，但另一个问题的链接有一个对我有用的版本。似乎我的问题是我的 javascript 无法正常工作，我忘记发布了，因为我认为这主要是一个 css 问题