Bootstrap中的子菜單下拉列表

Question

我是使用Bootstrap的新手，JS不是我最強的語言，所以我很難實現我正在尋找的東西。

我有一個用PHP生成的網站菜單，如下所示：

<?php
$products_menu = '';
$sql1 = "SELECT * FROM headings";
$stmt1 = DB::run($sql1);
while($row = $stmt1->fetch(PDO::FETCH_ASSOC)){
    $heading_id = $row['id'];
    $heading = $row['heading'];

    $products_menu .= '<li class="dropdown-item d-block">';
    $products_menu .= '<a class="submenu-item" href="store#'.$heading_id.'">'.$heading.'</a>';
    $products_menu .= '<ul class="dropdown-submenu">';

    $params = [$heading_id];
    $sql = "SELECT categories.category,categories.url FROM categories INNER JOIN category_headings on categories.id=category_headings.category WHERE category_headings.heading=?";
    $stmt = DB::run($sql,$params);
    while($row = $stmt->fetch(PDO::FETCH_ASSOC)){
        $category = $row['category'];
        $url = $row['url'];

        $products_menu .= '<li class="d-block"><a href="category/'.$url.'">'.$category.'</a></li>';
    }
    $products_menu .= '</ul>';
    $products_menu .= '</li>';
}
?>

<nav class="navbar navbar-expand-lg">
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
        <img src="media/icons/menu.png" alt="Lifting365 Menu" class="icon">
    </button>
    <div class="collapse navbar-collapse" id="navbarSupportedContent">
        <ul class="navbar-nav mr-auto">
            <li class="nav-item text-center"><a class="nav-link nav" href="">Home</a></li>
            <li class="nav-item text-center dropdown">
                <a class="nav-link nav dropdown-toggle" href="#" data-toggle="dropdown" aria-expanded="false">Products</a>
                <ul class="dropdown-menu">
                    <?php echo $products_menu; ?>
                </ul>
            </li>
            <li class="nav-item text-center"><a class="nav-link nav" href="blog">Blog</a></li>
            <li class="nav-item text-center"><a class="nav-link nav" href="about">About</a></li>
            <li class="nav-item text-center"><a class="nav-link nav" href="contact">Contact</a></li>
        </ul>
    </div>
</nav>

我希望第一個下拉菜單位於父標題之外。

然后，第一個下拉列表中的每個項目也應該是可點擊的，以帶您到商店頁面上的該標題。

懸停在第一個下拉菜單項上應該顯示其子菜單。

編輯

我不想將生成的整個HTML發布為巨大的，所以我刪除了前幾個標題的示例，只列出了每個標題的前幾個類別

<div class="page-header header-bottom">
    <div class="container">
        <div class="row">

            <div class="col-lg-4 col-md-5 col-sm-5 col-xs-5">
                <a href="/"><img src="media/logo.png" alt="Logo" class="logo"></a>
            </div>

            <div class="col-lg-4 col-md-5 col-sm-5 col-xs-5">
                <form class="form-inline search">
                    <div class="input-group">
                        <input class="form-control" type="text" placeholder="Search" aria-label="Search">
                            <div class="input-group-append">
                            <button class="btn btn-default bg-orange" type="submit">
                            <img src="media/icons/search.png" alt="search icon" class="icon">
                            </button>
                        </div>
                    </div>
                </form>         
            </div>

            <div class="col-lg-4 col-md-2 col-sm-2 col-xs-2">

                <nav class="navbar navbar-expand-lg">
                    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
                        <img src="media/icons/menu.png" alt="Menu" class="icon">
                    </button>
                    <div class="collapse navbar-collapse" id="navbarSupportedContent">
                        <ul class="navbar-nav mr-auto">
                            <li class="nav-item text-center"><a class="nav-link nav" href="">Home</a></li>
                            <li class="nav-item text-center dropdown">
                                <a class="nav-link nav dropdown-toggle" href="#" data-toggle="dropdown" aria-expanded="false">Products</a>
                                <ul class="dropdown-menu">
                                    <li class="dropdown-item d-block">
                                        <a class="submenu-item" href="store#1">Lifters &amp; Accessories</a>
                                        <ul class="dropdown-submenu">
                                            <li class="d-block"><a href="category/Hooks-Weld-On-Hooks">Hooks - Weld On Hooks</a></li>
                                            <li class="d-block"><a href="category/Manhole-Cover-Lifters">Manhole Cover Lifters</a></li>
                                            <li class="d-block"><a href="category/Salt-Spreaders">Salt Spreaders</a></li>
                                            <li class="d-block"><a href="category/ID-Tags">ID Tags</a></li>
                                        </ul>
                                    </li>
                                    <li class="dropdown-item d-block">
                                        <a class="submenu-item" href="store#2">Lifting &amp; Measurement Attachments</a>
                                        <ul class="dropdown-submenu">
                                            <li class="d-block"><a href="category/Big-Bag-Lifters">Big Bag Lifters</a></li>
                                            <li class="d-block"><a href="category/Crane-Slung-Safety-Cages">Crane Slung Safety Cages</a></li>
                                            <li class="d-block"><a href="category/Gas-Bottle-Handlers">Gas Bottle Handlers</a></li>
                                            <li class="d-block"><a href="category/Weighers-Crane-Weighers">Weighers - Crane Weighers</a></li>
                                        </ul>
                                    </li>
                                    <li class="dropdown-item d-block">
                                        <a class="submenu-item" href="store#3">Forklift &amp; Crane Attachments</a>
                                        <ul class="dropdown-submenu">
                                            <li class="d-block"><a href="category/Forklift-Magnetic-Sweepers">Forklift Magnetic Sweepers</a></li>
                                            <li class="d-block"><a href="category/Wheelie-Bin-Tippers">Wheelie Bin Tippers</a></li>
                                            <li class="d-block"><a href="category/Forklift-Safety-Cages">Forklift Safety Cages</a></li>
                                            <li class="d-block"><a href="category/Fork-Extensions">Fork Extensions</a></li>
                                            <li class="d-block"><a href="category/Forklift-Base-Emptying-Stillages">Forklift Base Emptying Stillages</a></li>
                                        </ul>
                                    </li>
                                    <li class="dropdown-item d-block">
                                        <a class="submenu-item" href="store#4">Forklift Hooks &amp; Jibs</a>
                                        <ul class="dropdown-submenu">
                                            <li class="d-block"><a href="category/Forklift-Mounted-Hook-Fixed">Forklift Mounted Hook - Fixed</a></li>
                                            <li class="d-block"><a href="category/Forklift-Mounted-Hook-Adjustable">Forklift Mounted Hook - Adjustable</a></li>
                                            <li class="d-block"><a href="category/Crane-Spreader-Beams">Crane Spreader Beams</a></li>
                                            <li class="d-block"><a href="category/Forklift-Jibs">Forklift Jibs</a></li>
                                        </ul>
                                    </li>
                                </ul>
                            </li>
                            <li class="nav-item text-center"><a class="nav-link nav" href="blog">Blog</a></li>
                            <li class="nav-item text-center"><a class="nav-link nav" href="page/About">About Us</a></li>
                            <li class="nav-item text-center"><a class="nav-link nav" href="contact">Contact Us</a></li>
                        </ul>
                    </div>
                </nav>
            </div>
        </div>
    </div>
</div>

Answer 1

我把它與Bootstrap 4和一些自定義CSS放在一起：

 .navbar-nav a { color: #fff !important; } .navbar-nav a:hover { color: #ddd !important; } .navbar-nav .submenu.level-2 { padding-left: 1.5rem; } .navbar-nav .dropdown-toggle::after { display: none; } @media (min-width: 768px) { .navbar-nav .dropdown .submenu { position: absolute; top: 100%; display: none; } .navbar-nav .dropdown .submenu li { display: block; } .navbar-nav .dropdown .submenu li a { display: block; white-space: nowrap; text-decoration: none; } .navbar-nav .dropdown .submenu.level-1 { right: 0; left: auto; } .navbar-nav .dropdown .submenu.level-2 { padding-left: 0; top: 0; right: 100%; left: auto; } .navbar-nav .dropdown:hover .submenu.level-1 { display: block; } .navbar-nav .dropdown:hover .submenu.level-1 li { position: relative; } .navbar-nav .dropdown:hover .submenu.level-1 li:hover .submenu.level-2 { display: block; } .navbar-nav .dropdown-toggle::after { display: inline-block; } } 

 <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.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> <nav class="navbar navbar-expand-md bg-dark navbar-dark"> <a class="navbar-brand" href="#">Logo</a> <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#collapsibleNavbar"> <span class="navbar-toggler-icon"></span> </button> <div class="collapse navbar-collapse" id="collapsibleNavbar"> <ul class="navbar-nav ml-auto"> <li class="nav-item"> <a class="nav-link" href="#">Home</a> </li> <li class="nav-item"> <a class="nav-link" href="#">Career</a> </li> <li class="nav-item dropdown"> <a class="nav-link dropdown-toggle" href="#">Info</a> <ul class="list-unstyled bg-dark text-light submenu level-1"> <li><a class="nav-link" href="#">About</a> <ul class="list-unstyled bg-dark text-light submenu level-2"> <li><a class="nav-link" href="#">Mission</a></li> <li><a class="nav-link" href="#">Vision</a></li> </ul> </li> <li><a class="nav-link" href="#">Clients</a></li> <li><a class="nav-link" href="#">Contact Us</a></li> </ul> </li> </ul> </div> </nav> 

這是一個帶有SCSS而不是純CSS的jsFiddle 。

我不知道你要找的結果有多接近，但我希望它有所幫助。

Answer 2

根據我的理解，您正在尋找嵌套的子菜單。 如果，以下是同樣的解決方案。

 .dropdown-submenu { position: relative; } .dropdown-submenu:hover>.dropdown-menu { top: 0; left: -10rem; /* 10rem is the min-width of dropdown-menu */ margin-top: -6px; display:block } .dropdown:hover>.dropdown-menu{ display:block } /* rotate caret on hover */ .dropdown-menu>li>a:hover:after { text-decoration: underline; transform: rotate(-90deg); } 

 <!DOCTYPE html> <html> <head> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.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> </head> <body> <nav class="navbar navbar-expand-md navbar-light bg-light"> <a class="navbar-brand pb-2" href="#">Navbar</a> <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNavDropdown" aria-controls="navbarNavDropdown" aria-expanded="false" aria-label="Toggle navigation"> <span class="navbar-toggler-icon"></span> </button> <div class="collapse navbar-collapse" id="navbarNavDropdown"> <ul class="navbar-nav ml-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="http://example.com" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false"> Dropdown </a> <ul class="dropdown-menu dropdown-menu-right" aria-labelledby="navbarDropdownMenuLink"> <li><a class="dropdown-item" href="#">Action</a></li> <li><a class="dropdown-item" href="#">Another action</a></li> <li class="dropdown-submenu"><a class="dropdown-item dropdown-toggle" href="#">Submenu wider text</a> <ul class="dropdown-menu"> <li><a class="dropdown-item" href="#">Submenu</a></li> <li><a class="dropdown-item" href="#">Submenu0</a></li> <li class="dropdown-submenu"><a class="dropdown-item dropdown-toggle" href="#">Submenu 1</a> <ul class="dropdown-menu"> <li><a class="dropdown-item" href="#">Subsubmenu1</a></li> <li><a class="dropdown-item" href="#">Subsubmenu1</a></li> </ul> </li> <li class="dropdown-submenu"><a class="dropdown-item dropdown-toggle" href="#">Submenu 2</a> <ul class="dropdown-menu"> <li><a class="dropdown-item" href="#">Subsubmenu2</a></li> <li><a class="dropdown-item" href="#">Subsubmenu2</a></li> </ul> </li> </ul> </li> </ul> </li> </ul> </div> </nav> </body> </html> 

來源Skelly Codeply