css - 更改不透明度 Bootstrap 导航栏

Question

我试图在这段代码上让我的导航栏半透明，但我做不到:

 <nav class="navbar navbar-default navbar-fixed-top transparent" >
 <div class="container">
 <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">
    <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="/">Home <span class="sr-only">(current)</span></a></li>
    <li><a href="/searches">Searches</a></li>
    <li><a href="/contact">Contact</a></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 class="dropdown">
      <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-expanded="false">Legal <span class="caret"></span></a>
       <ul class="dropdown-menu" role="menu">
        <li><a href="/terms">Terms</a></li>
        <li><a href="/dmca">DMCA</a></li>
        <li><a href="/rta">RTA</a></li>
        <li class="divider"></li>
        <li><a href="/contact">Contact</a></li>

Answer 1

在你的代码中试试这个，它对我有用 -

给导航一个id

像这样-

<nav class="navbar navbar-default navbar-fixed-top transparent" id="nav1">

然后在你的 css 中应用它-

#nav1
{  
    background-color:#F00; /*whichever you want*/
    opacity: 0.5; 
    filter:(opacity=50);       
}