html - bootstrap 4 导航栏的背景颜色问题

Question

如标题中所述，我的导航栏有问题。我不能用 rgba 改变背景颜色和他的不透明度，所以如果你有想法，你能帮我吗？

#navbarr {
  background-color: rgba(0, 0, 0, 0.8);
}

<div class="navbar navbar-dark bg-dark fixed-top navbar-expand-md" id='navbarr' role="navigation">
      <div class="container">
        <button type="button" class="navbar-toggler" data-toggle="collapse" data-target=".navbar-collapse"> <span class="sr-only" id="asupr">Toggle navigation</span>
        &#x2630;</button>
        <a class="navbar-brand" href="index.html">Portfolio</a>
        <div class="navbar-collapse collapse">
          <ul class="nav navbar-nav ml-auto">
            <li class="active nav-item"><a href="index.html" class="nav-link">Accueil</a>
            </li>
            <li class="nav-item"><a href="works.html" class="smoothscroll nav-link">Travaux</a>
            </li>
            <li class="nav-item"><a href="contact.html" class="smoothscroll nav-link">Contact</a>
            </li>
          </ul>
        </div>
      </div>
    </div>

Answer 1

删除 bg-dark 类。

<div class="navbar navbar-dark fixed-top navbar-expand-md" id='navbarr' role="navigation">
      <div class="container">
        <button type="button" class="navbar-toggler" data-toggle="collapse" data-target=".navbar-collapse"> <span class="sr-only" id="asupr">Toggle navigation</span>
        &#x2630;</button>
        <a class="navbar-brand" href="index.html">Portfolio</a>
        <div class="navbar-collapse collapse">
          <ul class="nav navbar-nav ml-auto">
            <li class="active nav-item"><a href="index.html" class="nav-link">Accueil</a>
            </li>
            <li class="nav-item"><a href="works.html" class="smoothscroll nav-link">Travaux</a>
            </li>
            <li class="nav-item"><a href="contact.html" class="smoothscroll nav-link">Contact</a>
            </li>
          </ul>
        </div>
      </div>
    </div>