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。我已经尝试过向手风琴和卡片中添加一些包含position: relative的样式，以及不同的z-index值，但是没有机会。有什么想法吗？

更新：我已将代码段粘贴到tryit editor

中

更新2：我还完成了上面的代码的截屏视频：

Answer 1

这是因为在您的卡类中添加了隐藏的溢出内容。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>

Bootstrap：手风琴顶部的下拉菜单

2 个答案: