页脚栏未显示为页脚

Question

我正在尝试从入门模板 bootstrap4 添加 html 页面底部的粘性页脚。不幸的是，页脚仍然在页面中间，而不是作为页脚。

我不明白为什么模板中的两个 css 文件（starter-template.css、sticky-footer.css）都位于 index.html

的同一层

<!doctype html>
<html lang="en">

<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
  <meta name="description" content="">
  <meta name="author" content="Mark Otto, Jacob Thornton, and Bootstrap contributors">
  <meta name="generator" content="Jekyll v4.1.1">
  <title>Boostrap NavBar & Footer</title>

  <link rel="canonical" href="https://getbootstrap.com/docs/4.5/examples/starter-template/">

  <!-- Bootstrap core CSS -->
  <link href="assets/dist/css/bootstrap.min.css" rel="stylesheet">

  <style>
    .bd-placeholder-img {
      font-size: 1.125rem;
      text-anchor: middle;
      -webkit-user-select: none;
      -moz-user-select: none;
      -ms-user-select: none;
      user-select: none;
    }
    
    @media (min-width: 768px) {
      .bd-placeholder-img-lg {
        font-size: 3.5rem;
      }
    }
  </style>
  <!-- Custom styles for this template -->
  <link href="starter-template.css" rel="stylesheet">
  <link href="sticky-footer.css" rel="stylesheet">
</head>

<body class="d-flex flex-column h-100">
  <nav class="navbar navbar-expand-md navbar-dark bg-dark fixed-top">
    <a class="navbar-brand" href="index.html">NavBar</a>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarsExampleDefault" aria-controls="navbarsExampleDefault" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>

    <div class="collapse navbar-collapse" id="navbarsExampleDefault">
      <ul class="navbar-nav mr-auto">
        <li class="nav-item disabled">
          <a class="nav-link dropdown-toggle" href="#" id="dropdown01" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Menu</a>
          <div class="dropdown-menu" aria-labelledby="dropdown01">
            <a class="dropdown-item" href="#">One</a>
            <a class="dropdown-item" href="#">Two</a>
            <a class="dropdown-item" href="#">Three</a>
          </div>
        </li>
      </ul>
      <form class="form-inline my-2 my-lg-0">
        <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
        <button class="btn btn-secondary my-2 my-sm-0" type="submit">Search</button>
      </form>
    </div>
  </nav>

  <main role="main" class="container">

    <div class="starter-template">
      <h1>Sticky footer</h1><br>
      <p class="lead">Pin a footer to the bottom of the viewport in desktop browsers with this custom HTML and CSS.</p>

    </div>

  </main>
  <!-- /.container -->

  <script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" integrity="sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj" crossorigin="anonymous"></script>
  <script>
    window.jQuery || document.write('<script src="../assets/js/vendor/jquery.slim.min.js"><\/script>')
  </script>
  <script src="../assets/dist/js/bootstrap.bundle.min.js"></script>


  <footer class="footer mt-auto py-3">
    <div class="container">
      <div class="row">
        <span class="text-muted">Place sticky footer content here.</span>
      </div>
    </div>
  </footer>

</body>

</html>

Answer 1

将 html 和正文设置为 100% 高度：

html, body {
  height: 100%;
}

<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css" rel="stylesheet"/>
<body class="d-flex flex-column h-100">
  <nav class="navbar navbar-expand-md navbar-dark bg-dark fixed-top">
    <a class="navbar-brand" href="index.html">NavBar</a>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarsExampleDefault"
      aria-controls="navbarsExampleDefault" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>

    <div class="collapse navbar-collapse" id="navbarsExampleDefault">
      <ul class="navbar-nav mr-auto">
        <li class="nav-item disabled">
          <a class="nav-link dropdown-toggle" href="#" id="dropdown01" data-toggle="dropdown" aria-haspopup="true"
            aria-expanded="false">Menu</a>
          <div class="dropdown-menu" aria-labelledby="dropdown01">
            <a class="dropdown-item" href="#">One</a>
            <a class="dropdown-item" href="#">Two</a>
            <a class="dropdown-item" href="#">Three</a>
          </div>
        </li>
      </ul>
      <form class="form-inline my-2 my-lg-0">
        <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
        <button class="btn btn-secondary my-2 my-sm-0" type="submit">Search</button>
      </form>
    </div>
  </nav>

  <main role="main" class="container">

    <div class="starter-template">
      <h1>Sticky footer</h1><br>
      <p class="lead">Pin a footer to the bottom of the viewport in desktop browsers with this custom HTML and CSS.</p>

    </div>

  </main><!-- /.container -->

  <script src="https://code.jquery.com/jquery-3.5.1.slim.min.js"
    integrity="sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj"
    crossorigin="anonymous"></script>
  <script>window.jQuery || document.write('<script src="../assets/js/vendor/jquery.slim.min.js"><\/script>')</script>
  <script src="../assets/dist/js/bootstrap.bundle.min.js"></script>


  <footer class="footer mt-auto py-3">
    <div class="container">
      <div class="row">
        <span class="text-muted">Place sticky footer content here.</span>
      </div>
    </div>
  </footer>

Answer 2

将position: sticky;与bottom:0

结合使用

body{
margin:0;}
footer {
    position: sticky;
    bottom: 0;
    left: 0;
    right: 0;
    width: 100%;
    padding: 10px;
    background: #ddd;
}

<!doctype html>
<html lang="en">

<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
  <meta name="description" content="">
  <meta name="author" content="Mark Otto, Jacob Thornton, and Bootstrap contributors">
  <meta name="generator" content="Jekyll v4.1.1">
  <title>Boostrap NavBar & Footer</title>

  <link rel="canonical" href="https://getbootstrap.com/docs/4.5/examples/starter-template/">

  <!-- Bootstrap core CSS -->
  <link href="assets/dist/css/bootstrap.min.css" rel="stylesheet">

  <style>
    .bd-placeholder-img {
      font-size: 1.125rem;
      text-anchor: middle;
      -webkit-user-select: none;
      -moz-user-select: none;
      -ms-user-select: none;
      user-select: none;
    }
    
    @media (min-width: 768px) {
      .bd-placeholder-img-lg {
        font-size: 3.5rem;
      }
    }
  </style>
  <!-- Custom styles for this template -->
  <link href="starter-template.css" rel="stylesheet">
  <link href="sticky-footer.css" rel="stylesheet">
</head>

<body class="d-flex flex-column h-100">
  <nav class="navbar navbar-expand-md navbar-dark bg-dark fixed-top">
    <a class="navbar-brand" href="index.html">NavBar</a>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarsExampleDefault" aria-controls="navbarsExampleDefault" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>

    <div class="collapse navbar-collapse" id="navbarsExampleDefault">
      <ul class="navbar-nav mr-auto">
        <li class="nav-item disabled">
          <a class="nav-link dropdown-toggle" href="#" id="dropdown01" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Menu</a>
          <div class="dropdown-menu" aria-labelledby="dropdown01">
            <a class="dropdown-item" href="#">One</a>
            <a class="dropdown-item" href="#">Two</a>
            <a class="dropdown-item" href="#">Three</a>
          </div>
        </li>
      </ul>
      <form class="form-inline my-2 my-lg-0">
        <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
        <button class="btn btn-secondary my-2 my-sm-0" type="submit">Search</button>
      </form>
    </div>
  </nav>

  <main role="main" class="container">

    <div class="starter-template">
      <h1>Sticky footer</h1><br>
      <p class="lead">Pin a footer to the bottom of the viewport in desktop browsers with this custom HTML and CSS.</p>

    </div>

  </main>
  <!-- /.container -->

  <script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" integrity="sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj" crossorigin="anonymous"></script>
  <script>
    window.jQuery || document.write('<script src="../assets/js/vendor/jquery.slim.min.js"><\/script>')
  </script>
  <script src="../assets/dist/js/bootstrap.bundle.min.js"></script>


  <footer class="footer mt-auto py-3">
    <div class="container">
      <div class="row">
        <span class="text-muted">Place sticky footer content here.</span>
      </div>
    </div>
  </footer>

</body>

</html>

页脚栏未显示为页脚

Footer bar not displayed as a footer

html

css

footer

bootstrap-4