Bootstrap：手风琴顶部的下拉菜单

Question

我有一个bootstrap 4下拉菜单，它位于bootstrap手风琴的主体内：

 <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.2.1/css/bootstrap.min.css" integrity="sha384-GJzZqFGwb1QTTN6wy59ffF1BuGJpLSa9DkKMp0DgiMDm4iYMj70gZWKYbI706tWS" crossorigin="anonymous"> <script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.6/umd/popper.min.js" integrity="sha384-wHAiFfRlMFy6i5SRaxvfOCifBUQy1xHdJ/yoi7FRNXMRBu5WHdZYu1hA6ZOblgut" crossorigin="anonymous"></script> <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.2.1/js/bootstrap.min.js" integrity="sha384-B0UglyR+jN6CkvvICOB2joaf5I4l3gm9GU6Hc1og6Ls7i6U/mkkaduKaBhlAXv9k" crossorigin="anonymous"></script> <div class="accordion mb-3" id="testAccordion"> <div class="card"> <div class="card-header" id="accordionAHeading"> <h2 class="mb-0"> <button class="btn btn-link" type="button" data-toggle="collapse" data-target="#accordionACollapse"> Lalala </button> </h2> </div> <div id="accordionACollapse" class="collapsed collapse show" data-parent="#testAccordion"> <div class="card-body"> <h5>Lalala</h5> <div class="dropdown" id="addElementDropdown"> <button class="btn btn-primary dropdown-toggle" type="button" id="addElementDropdownButton" data-toggle="dropdown">Dropdown</button> <div class="dropdown-menu" aria-labelledby="addElementDropdownButton"> <a class="dropdown-item" href="#">Item 1</a> <a class="dropdown-item" href="#">Item 2</a> <a class="dropdown-item" href="#">Item 3</a> <a class="dropdown-item" href="#">Item 4</a> <a class="dropdown-item" href="#">Item 5</a> </div> </div> </div> </div> </div> <div class="card"> <div class="card-header" id="accordionBHeading"> <h2 class="mb-0"> <button class="btn btn-link collapsed" type="button" data-toggle="collapse" data-target="#accordionBCollapse"> Test </button> </h2> </div> <div id="accordionBCollapse" class="collapse collapsed" data-parent="#testAccordion"> <div class="card-body"> <h5>Test</h5> <div class="dropdown" id="addElementDropdown"> <button class="btn btn-primary dropdown-toggle" type="button" id="addElementDropdownButton" data-toggle="dropdown">Dropdown</button> <div class="dropdown-menu" aria-labelledby="addElementDropdownButton"> <a class="dropdown-item" href="#">Item 1</a> <a class="dropdown-item" href="#">Item 2</a> <a class="dropdown-item" href="#">Item 3</a> <a class="dropdown-item" href="#">Item 4</a> <a class="dropdown-item" href="#">Item 5</a> </div> </div> </div> </div> </div> </div> 

不幸的是，下拉菜单位于手风琴后面。 我已经尝试添加一些包含position: relative样式position: relative对于手风琴和卡片，以及不同的z-index -values，但是没有机会。 有任何想法吗？

更新：我已将代码段粘贴到tryit编辑器中

更新2：我也做了上面的代码的截屏视频：

Answer 1

这是因为隐藏的溢出内容已添加到您的卡类中。 将此添加到您的CSS

.accordion .card {
    overflow: inherit;
}

Answer 2

您必须覆盖为下拉列表自动生成的CSS。 添加以下CSS：

 .dropdown-toggle { float: left; } .dropdown-menu.show { position: relative !important; clear: both; margin-top: 0; transform: none !important; } 

 <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.2.1/css/bootstrap.min.css" integrity="sha384-GJzZqFGwb1QTTN6wy59ffF1BuGJpLSa9DkKMp0DgiMDm4iYMj70gZWKYbI706tWS" crossorigin="anonymous"> <script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.6/umd/popper.min.js" integrity="sha384-wHAiFfRlMFy6i5SRaxvfOCifBUQy1xHdJ/yoi7FRNXMRBu5WHdZYu1hA6ZOblgut" crossorigin="anonymous"></script> <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.2.1/js/bootstrap.min.js" integrity="sha384-B0UglyR+jN6CkvvICOB2joaf5I4l3gm9GU6Hc1og6Ls7i6U/mkkaduKaBhlAXv9k" crossorigin="anonymous"></script> <div class="accordion mb-3" id="testAccordion"> <div class="card"> <div class="card-header" id="accordionAHeading"> <h2 class="mb-0"> <button class="btn btn-link" type="button" data-toggle="collapse" data-target="#accordionACollapse"> Lalala </button> </h2> </div> <div id="accordionACollapse" class="collapsed collapse show" data-parent="#testAccordion"> <div class="card-body"> <h5>Lalala</h5> <div class="dropdown" id="addElementDropdown"> <button class="btn btn-primary dropdown-toggle" type="button" id="addElementDropdownButton" data-toggle="dropdown">Dropdown</button> <div class="dropdown-menu" aria-labelledby="addElementDropdownButton"> <a class="dropdown-item" href="#">Item 1</a> <a class="dropdown-item" href="#">Item 2</a> <a class="dropdown-item" href="#">Item 3</a> <a class="dropdown-item" href="#">Item 4</a> <a class="dropdown-item" href="#">Item 5</a> </div> </div> </div> </div> </div> <div class="card"> <div class="card-header" id="accordionBHeading"> <h2 class="mb-0"> <button class="btn btn-link collapsed" type="button" data-toggle="collapse" data-target="#accordionBCollapse"> Test </button> </h2> </div> <div id="accordionBCollapse" class="collapse collapsed" data-parent="#testAccordion"> <div class="card-body"> <h5>Test</h5> <div class="dropdown" id="addElementDropdown"> <button class="btn btn-primary dropdown-toggle" type="button" id="addElementDropdownButton" data-toggle="dropdown">Dropdown</button> <div class="dropdown-menu" aria-labelledby="addElementDropdownButton"> <a class="dropdown-item" href="#">Item 1</a> <a class="dropdown-item" href="#">Item 2</a> <a class="dropdown-item" href="#">Item 3</a> <a class="dropdown-item" href="#">Item 4</a> <a class="dropdown-item" href="#">Item 5</a> </div> </div> </div> </div> </div> </div>