css - 删除闪烁的 effet bootstrap 下拉菜单

Question

在修改 Bootstrap vanilla 的 css 时，我发现当您单击下拉菜单然后单击其外部(例如在正文中)时出现奇怪的闪烁效果:

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet" />
<style>
  .navbar-default {
    background-color: #222;
  }
  .navbar-default .navbar-brand,
  .navbar-default .navbar-brand:hover,
  .navbar-default .navbar-nav > li > a {
    color: #FFF;
  }
  .navbar-default .navbar-nav > li > a:hover,
  .navbar-default .navbar-nav > li > a:focus,
  .navbar-default .navbar-nav > .dropdown > a:focus,
  .navbar-default .navbar-nav > .open {
    background-color: #444;
    color: #FFF;
  }
  @media (min-width: 3000px) and (max-width: 3000px) {
    .collapse {
      display: none !important;
    }
  }
</style>
<script src="https://code.jquery.com/jquery-1.11.3.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<nav class="navbar navbar-default">
  <div class="container-fluid">
    <!-- Brand and toggle get grouped for better mobile display -->
    <div class="navbar-header">
      <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1" aria-expanded="false">
        <span class="sr-only">Toggle navigation</span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <a class="navbar-brand" href="#">Brand</a>
    </div>

    <!-- Collect the nav links, forms, and other content for toggling -->
    <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
      <ul class="nav navbar-nav">
        <li><a href="#">Link <span class="sr-only">(current)</span></a>
        </li>
        <li><a href="#">Link</a>
        </li>
        <li class="dropdown">
          <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Dropdown <span class="caret"></span></a>
          <ul class="dropdown-menu">
            <li><a href="#">Action</a>
            </li>
            <li><a href="#">Another action</a>
            </li>
            <li><a href="#">Something else here</a>
            </li>
            <li role="separator" class="divider"></li>
            <li><a href="#">Separated link</a>
            </li>
            <li role="separator" class="divider"></li>
            <li><a href="#">One more separated link</a>
            </li>
          </ul>
        </li>
      </ul>
      <form class="navbar-form navbar-left" role="search">
        <div class="form-group">
          <input type="text" class="form-control" placeholder="Search">
        </div>
        <button type="submit" class="btn btn-default">Submit</button>
      </form>
      <ul class="nav navbar-nav navbar-right">
        <li><a href="#">Link</a>
        </li>
        <li class="dropdown">
          <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Dropdown <span class="caret"></span></a>
          <ul class="dropdown-menu">
            <li><a href="#">Action</a>
            </li>
            <li><a href="#">Another action</a>
            </li>
            <li><a href="#">Something else here</a>
            </li>
            <li role="separator" class="divider"></li>
            <li><a href="#">Separated link</a>
            </li>
          </ul>
        </li>
      </ul>
    </div>
    <!-- /.navbar-collapse -->
  </div>
  <!-- /.container-fluid -->
</nav>

要使代码段实际显示错误，您需要在整个页面中看到它。

---

我还做了一个 JSFiddle使事情更清楚，更容易解释。

您知道我应该使用哪个 css 选择器来修复它吗？

Answer 1

您需要的元素是 a.dropdown-toggle。我不知道 bootstrap 在设计它的样式时有多具体，或者即使它使用内联样式，但如果你使用 !important 你可以看到闪烁停止。

.dropdown-toggle {
     background-color: transparent !important;   
}

Updated fiddle

更新:Bootstrap 使用:.nav .open>a, .nav .open>a:focus, .nav .open>a:hover