html - Bootstrap透明菜单

Question

我想使我的 Bootstrap 菜单具有透明背景。滚动后将颜色更改为灰色。我尝试了我在这里看到的一切，但到目前为止没有成功。

这是我的代码:

<nav class="navbar  transparent navbar-inverse navbar-fixed-top">
<div class="container-fluid">
<div class="navbar-header">
  <button type="button" class="navbar-toggle" data-toggle="collapse" 
    data-target="#myNavbar">
    <span class="icon-bar"></span>
    <span class="icon-bar"></span>
    <span class="icon-bar"></span>                        
  </button>
  <a class="navbar-brand" href="#">WebSiteName</a>
</div>
<div class="collapse navbar-collapse" id="myNavbar">
  <ul class="nav navbar-nav">
    <li class="active"><a href="#">Home</a></li>
    <li class="dropdown">
      <a class="dropdown-toggle" data-toggle="dropdown" href="#">Page 1 
     <span class="caret"></span></a>
      <ul class="dropdown-menu">
        <li><a href="#">Page 1-1</a></li>
        <li><a href="#">Page 1-2</a></li>
        <li><a href="#">Page 1-3</a></li>
      </ul>
    </li>
    <li><a href="#">Page 2</a></li>
    <li><a href="#">Page 3</a></li>
  </ul>
  <ul class="nav navbar-nav navbar-right">
    <li><a href="#"><span class="glyphicon glyphicon-user"></span> Sign Up</a></li>
    <li><a href="#"><span class="glyphicon glyphicon-log-in"></span> Login</a></li>
  </ul>
</div>

Answer 1

如果这就是您要找的，请告诉我..

$(document).ready(function() {
  $(window).scroll(function() {
    var scroll = $(window).scrollTop();
    if (scroll > 10) {
      $(".transparent").css("background", "grey");
    } else {
      $(".transparent").css("background", "transparent");
    }
  })
})

body {
  margin: 0;
  padding: 0;
  height: 1000px;
}

.transparent {
  position: fixed;
  top: 0;
  background: transparent;
  width: 100%;
  height: 50px;
}

.transparent ul {
  list-style-type: none;
  padding: 0;
}

.transparent ul li {
  display: inline-block;
  width: 100px;
  color: red;
}

.grey {
  position: fixed;
  top: 0;
  background: #333;
  width: 100%;
  height: 50px;
}

<link href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<nav class="navbar  transparent navbar-inverse navbar-fixed-top">
  <div class="container-fluid">
    <div class="navbar-header">
      <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#myNavbar">
    <span class="icon-bar"></span>
    <span class="icon-bar"></span>
    <span class="icon-bar"></span>                        
  </button>
      <a class="navbar-brand" href="#">WebSiteName</a>
    </div>
    <div class="collapse navbar-collapse" id="myNavbar">
      <ul class="nav navbar-nav">
        <li class="active"><a href="#">Home</a></li>
        <li class="dropdown">
          <a class="dropdown-toggle" data-toggle="dropdown" href="#">Page 1 
     <span class="caret"></span></a>
          <ul class="dropdown-menu">
            <li><a href="#">Page 1-1</a></li>
            <li><a href="#">Page 1-2</a></li>
            <li><a href="#">Page 1-3</a></li>
          </ul>
        </li>
        <li><a href="#">Page 2</a></li>
        <li><a href="#">Page 3</a></li>
      </ul>
      <ul class="nav navbar-nav navbar-right">
        <li><a href="#"><span class="glyphicon glyphicon-user"></span> Sign Up</a></li>
        <li><a href="#"><span class="glyphicon glyphicon-log-in"></span> Login</a></li>
      </ul>
    </div>