删除悬停背景下拉引导程序 4

Question

<li class="nav-item active dropdown">
        <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
          Dropdown link
        </a>
        <div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
          <a class="dropdown-item" href="#">Action</a>
          <a class="dropdown-item" href="#">Another action</a>
          <a class="dropdown-item" href="#">Something else here</a>
        </div>
      </li>

我编写了这段代码来使用引导程序创建一个下拉菜单（非常简单），现在我尝试在将鼠标悬停在下拉列表内的项目上时删除背景，但不知何故它们始终保持白色。

这是CSS

.dropdown-menu{
  background-color: transparent;
  border: transparent;
  border: none;
}
.dropdown-menu .dropdown-item > li > a:hover {
  background-image: none;
  background-color: #000;
}

Answer 1

添加.bg-transparent到元素中.dropdown-item。完毕。

Answer 2

最简单的方法是在下拉菜单中创建一个新类并应用 css

检查这个小提琴，更新小提琴https://jsfiddle.net/rb87gwzj/4/或这个片段

.dropdown-menu{
  background-color: transparent;
  border: transparent;
  border: none;
}
.dropdown-menu .dropdown-item > li > a:hover {
  background-image: none;
  
  background-color: #000!important;
}

.navbar {
  background: none;
}
.dropdown-content a:hover {
    background-color: transparent;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/tether/1.4.0/js/tether.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/css/bootstrap.min.css" rel="stylesheet"/>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/js/bootstrap.min.js"></script>


<nav class="navbar navbar-toggleable-md navbar-light bg-faded">
  <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
  </button>
  <a class="navbar-brand" href="index.html">
    <img src="images/logo.png" width="30" height="30" class="d-inline-block align-top" alt="">
  </a>
  <div class="collapse navbar-collapse" id="navbarNav">
    <ul class="navbar-nav">
      <li class="nav-item active">
        <a class="nav-link" href="index.html">Home</a>
      </li>
      <li class="nav-item active dropdown">
        <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
          Projects
        </a>
        <div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink" >
        <div class="dropdown-content">
        
      
          <a class="dropdown-item" href="#html">HTML5/CSS</a>
          <a class="dropdown-item" href="#python">Python</a>
          <a class="dropdown-item" href="#php">PHP</a>
          <a class="dropdown-item" href="#java">Java</a>
          <a class="dropdown-item" href="#csharp">C#</a>
  </div>
        </div>
      </li>
    </ul>
  </div>
</nav>

你应用了CSS，dropdown-menu .dropdown-item > li > a:hover但你的结构不一样，你的下拉菜单内没有下拉项，下拉项li内没有下拉项，请告诉我是否需要我解释更多