html - Bootstrap 4.1 悬停下拉菜单

Question

我有一个网站，我在其中使用 Bootstrap 4.1 创建了下拉菜单.此时，下拉菜单正在点击。

我用来创建下拉列表的 HTML 代码是:

<div class="collapse navbar-collapse text-center" id="navbarResponsive">
    <ul class="navbar-nav ml-auto">

        <li class="nav-item dropdown">
            <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenuLink" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
      main menu
    </a>
            <div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
                <a class="dropdown-item" href="#">A</a>
                <a class="dropdown-item" href="#">B</a>
                <a class="dropdown-item" href="#">C</a>
                <a class="dropdown-item" href="#">D</a>
            </div>
        </li>

        <button type="submit" onclick="location.href='/M';" class="btn btn-default">R</button>

    </ul>
 </div>

问题陈述:

我想知道我应该在上面的代码中进行哪些更改，以便我可以看到下拉项 (A,B,C,D) 悬停时。

Answer 1

你在找这个吗？

.navbar-nav li:hover>.dropdown-menu {
  display: block;
}

<link href="https://getbootstrap.com/docs/4.1/dist/css/bootstrap.min.css" rel="stylesheet" />
<div class="navbar-collapse text-center" id="navbarResponsive">
  <ul class="navbar-nav ml-auto">

    <li class="nav-item dropdown">
      <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenuLink" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
      main menu
    </a>
      <div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
        <a class="dropdown-item" href="#">A</a>
        <a class="dropdown-item" href="#">B</a>
        <a class="dropdown-item" href="#">C</a>
        <a class="dropdown-item" href="#">D</a>
      </div>
    </li>

    <button type="submit" onclick="location.href='/M';" class="btn btn-default">R</button>

  </ul>
</div>