如何在 Bootstrap 中显示黑色导航栏?

原文:https://www . geesforgeks . org/how-display-black-navigation-bar-in-bootstrap/

每个网站都使用导航栏,以使其更加用户友好,从而使网站导航变得容易,用户可以直接搜索他们感兴趣的主题。有以下两种方式显示黑色导航栏。

使用 。nav bar-深色 。BG-暗黑 :。navbar-dark 类的 bootstrap 使文本在 navbar 中变成白色。BG-深色类使导航条的背景色为黑色

示例:

超文本标记语言

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <meta name="viewport"
          content="width=device-width, initial-scale=1" />

    <link
      rel="stylesheet"
      href=
"https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css"/>

    <script src=
"https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js">
    </script>
    <script src=
"https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js">
    </script>
    <script src=
"https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js">
    </script>
  </head>
  <body>
    <nav class="navbar navbar-expand-lg navbar-dark bg-dark">
      <a class="navbar-brand" href="#">Geeksforgeeks</a>

      <div class="collapse navbar-collapse">
        <ul class="navbar-nav mr-auto">
          <li class="nav-item active">
            <a class="nav-link" href="#">Home</a>
          </li>
          <li class="nav-item">
            <a class="nav-link" href="#">Course</a>
          </li>
          <li class="nav-item">
            <a class="nav-link" href="#">Job Portal</a>
          </li>
        </ul>
        <form class="form-inline my-2 my-lg-0">
          <input
            class="form-control mr-sm-2"
            type="search"
            placeholder="Search"
            aria-label="Search"/>
          <button class="btn btn-light my-2 my-sm-0"
                  type="submit">
            Search
          </button>
        </form>
      </div>
    </nav>
  </body>
</html>

输出:

输出

使用 样式 属性设置背景颜色:我们可以使用 <导航> 标签的样式属性来设置导航条的背景颜色。

示例:

超文本标记语言

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1" />

    <link
      rel="stylesheet"
      href=
"https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css"/>

    <script src=
"https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js">
    </script>
    <script src=
"https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js">
    </script>
    <script src=
"https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js">
    </script>
  </head>
  <body>
    <nav
      class="navbar navbar-expand-lg navbar-dark"
      style="background-color: black"
    >
      <a class="navbar-brand" href="#">Geeksforgeeks</a>

      <div class="collapse navbar-collapse">
        <ul class="navbar-nav mr-auto">
          <li class="nav-item active">
            <a class="nav-link" href="#">Home</a>
          </li>
          <li class="nav-item">
            <a class="nav-link" href="#">Course</a>
          </li>
          <li class="nav-item">
            <a class="nav-link" href="#">Job Portal</a>
          </li>
        </ul>
        <form class="form-inline my-2 my-lg-0">
          <input
            class="form-control mr-sm-2"
            type="search"
            placeholder="Search"
            aria-label="Search"/>
          <button class="btn btn-light my-2 my-sm-0" 
                  type="submit">
            Search
          </button>
        </form>
      </div>
    </nav>
  </body>
</html>

输出: