bootstrap 3 navbar dropdown-toggle 不适用所有 CSS 样式

Question

我正在修改 bootstrap 3 导航栏，但某些 CSS 属性不适用...

我有这个导航栏 HTML：

<nav class="navbar navbar-default">
<div id="navbar-principal" class="container-fluid">

  <div id="navbar-colapsado" class="navbar-header">
    <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar" aria-expanded="false" aria-controls="navbar">
      <span class="sr-only">Toggle navigation</span>
      <span class="icon-bar"></span>
      <span class="icon-bar"></span>
      <span class="icon-bar"></span>
    </button>
    <a id="logo" class="navbar-brand" (click)="onClick('Inicio')" [class.active]="'Inicio'===itemSelected" [routerLink]="['/']"><img src="app/img/logo.jpg" alt="Logo"></a>
  </div>

  <div id="navbar" class="navbar-collapse collapse">
    <ul class="nav navbar-nav navbar-right">  
      <li><a [routerLink]="['/link']">Inicio</a></li>

      <li role="button" class="dropdown">
        <a class="dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Info<span class="caret">
        </span></a>
        <ul class="dropdown-menu">
          <li><a [routerLink]="['/linkA']">Mis Compras</a></li>
          <li><a [routerLink]="['/linkB']">Mis Facturas</a></li>
          <li><a [routerLink]="['/linkC']">Mi Cuenta</a></li>
        </ul>
      </li>        

      <li>Other links</li>
      <li>Other links</li>
      <li>Other links</li>

    </ul>
  </div><!--/.nav-collapse -->

  </div><!--/.container-fluid -->
</nav>

我从 CDN 加载 bootstrap 3 并用这个 CSS 代码覆盖：

:host .nav.navbar-nav.navbar-right > li.dropdown.open,
      .nav.navbar-nav.navbar-right > li.dropdown.open > a,
      .nav.navbar-nav.navbar-right > li.dropdown.open > a:hover{
  color: yellow;
  background-color: rgba(61, 164, 65, 1);
  border-color: #999999;
}

我的问题是在应用“颜色：黄色”时，“背景颜色”被完全忽略了。

我检查了 chrome 中的计算 css，似乎它是正确的......但是有些东西覆盖了我的风格！

我必须如何重写引导程序以避免这种情况？

Answer 1

刚刚在 css 中添加了父类以覆盖默认 css。

在下面的示例中，只有右侧导航栏被 css 覆盖。

.nav.navbar-nav.navbar-right > li.dropdown.open,
.nav.navbar-nav.navbar-right > li.dropdown.open > a,
.nav.navbar-nav.navbar-right > li.dropdown.open > a:hover{
  color: yellow;
  background: #3da441;
  border-color: #999999;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>
<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 class="active"><a href="#">Link <span class="sr-only">(current)</span></a></li>
        <li><a href="#">Link</a></li>        
      </ul>
      
      <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>

Answer 2

我终于找到问题了！

这是因为背景图像（包含在引导程序中）强加了背景颜色。

我已修复将此代码添加到组件 css 文件中：

.navbar-default .navbar-nav > li > .dropdown-menu > li > a:hover,
.navbar-default .navbar-nav > li > .dropdown-menu > li > a:focus {
  background-color: rgba(61, 164, 65, 0.1);
  background-image: none;
}
.navbar-default .navbar-nav .open .dropdown-menu > .active > a,
.navbar-default .navbar-nav .open .dropdown-menu > .active > a:hover,
.navbar-default .navbar-nav .open .dropdown-menu > .active > a:focus {
  background-color: rgba(61, 164, 65, 0.1);
  background-image: none;
}
.navbar-default .navbar-nav > .active > a,
.navbar-default .navbar-nav > .active > a:hover,
.navbar-default .navbar-nav > .active > a:focus {
  background-color: rgba(61, 164, 65, 0.1);
  background-image: none;
}
.navbar-default .navbar-nav > .open > a,
.navbar-default .navbar-nav > .open > a:hover,
.navbar-default .navbar-nav > .open > a:focus {
  background-color: rgba(61, 164, 65, 0.1);
  background-image: none;