悬停和超级菜单在导航项中不起作用

Question

我是引导程序的新手，并尝试在悬停上实现大型菜单。但是，大型菜单未显示。

.dropdown-content {
  display: none;
  position: absolute;
  background-color: #f9f9f9;
  width: 100%;
  left: 0;
  box-shadow: 0px 8px 16px 0px rgba(0, 0, 0, 0.2);
  z-index: 1;
}

.dropdown-content .header {
  background: red;
  padding: 16px;
  color: white;
}

nav ul li .dropdown:hover .dropdown-content {
  display: block;
}

nav ul li a {
  line-height: 59px;
  -webkit-transition: background-color 0.8s;
  -moz-transition: background-color 0.8s;
  -o-transition: background-color 0.8s;
  transition: background-color 0.8s;
}

nav ul li a:hover,
.dropdown:hover .dropbtn {
  background-color: #EFF3F6;
}

nav ul li a {
  position: relative;
}

nav ul li a:hover:after {
  content: "";
  display: block;
  border-left: 10px solid transparent;
  border-right: 10px solid transparent;
  border-bottom: 10px solid #7B8B93;
  position: absolute;
  left: 35%;
  bottom: 1px;
}

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.2.1/css/bootstrap.min.css" integrity="sha384-GJzZqFGwb1QTTN6wy59ffF1BuGJpLSa9DkKMp0DgiMDm4iYMj70gZWKYbI706tWS" crossorigin="anonymous">


<nav class="navbar navbar-expand-lg navbar-light bg-light">
  <a class="navbar-brand" href="#">Logo</a>
  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
                    <span class="navbar-toggler-icon"></span>
                </button>

  <div class="collapse navbar-collapse" id="navbarSupportedContent">
    <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">
        <a class="nav-link" href="#">Capabilities</a>
        <div class="dropdown">
          <div class="dropdown-content">
            <div class="header">
              <h2>Mega Menu</h2>
            </div>
            <div class="row">
              <div class="col-lg-4">
                <h3>Category 1</h3>
                <a href="#">Link 1</a>
                <a href="#">Link 2</a>
                <a href="#">Link 3</a>
              </div>
              <div class="col-lg-4">
                <h3>Category 2</h3>
                <a href="#">Link 1</a>
                <a href="#">Link 2</a>
                <a href="#">Link 3</a>
              </div>
              <div class="col-lg-4">
                <h3>Category 3</h3>
                <a href="#">Link 1</a>
                <a href="#">Link 2</a>
                <a href="#">Link 3</a>
              </div>
            </div>
          </div>
        </div>
      </li>
      <li class="nav-item">
        <a class="nav-link" href="#">Solutions</a>
      </li>
      <li class="nav-item">
        <a class="nav-link" href="#">Our Team</a>
      </li>
      <li class="nav-item">
        <a class="nav-link" href="#">Our Clients</a>
      </li>
      <li class="nav-item">
        <a class="nav-link" href="#">Blog</a>
      </li>
      <li class="nav-item">
        <a class="nav-link" href="#">Contact Us</a>
      </li>
      <li class="nav-item">
        <a class="nav-link" href="#"><i class="fas fa-search"></i></a>
      </li>
    </ul>
  </div>
</nav>
<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>

我不知道我在哪里弄错了。导航菜单项上的onHover时，不会弹出超级菜单。我已经尝试过display：block，但是它没有出现。有人可以帮我解决此问题。我将不胜感激。谢谢

Answer 1

在CSS中添加以下样式将解决您的问题。

  .dropdown{position:initial !important}
    .nav-link:hover + .dropdown .dropdown-content{
        display: block;
    }