Untuk solusi CSS murni, gulir setelah tanggal 2 <hr>. Yang pertama adalah jawaban awal (diberikan pada tahun 2016)
Kelemahan utama dari solusi di atas adalah mereka memiliki ketinggian tetap untuk footer.
Dan itu tidak memotongnya di dunia nyata, di mana orang menggunakan jutaan perangkat dan memiliki kebiasaan buruk untuk memutarnya ketika Anda tidak menduganya dan ** Poof! ** Ada konten halaman Anda di belakang catatan kaki!
Di dunia nyata, Anda memerlukan fungsi yang menghitung ketinggian footer dan secara dinamis menyesuaikan konten halaman padding-bottomuntuk mengakomodasi ketinggian itu. Dan Anda perlu menjalankan fungsi kecil ini di halaman loaddan resizeacara serta di footer DOMSubtreeModified(kalau-kalau footer Anda diperbarui secara dinamis secara tidak sinkron atau mengandung elemen animasi yang mengubah ukuran ketika berinteraksi dengan).
Berikut adalah bukti konsep, menggunakan jQuery v3.0.0dan Bootstrap v4-alpha, tetapi tidak ada alasan mengapa itu tidak bekerja pada versi yang lebih rendah dari masing-masing.
jQuery(document).ready(function($) {
$.fn.accomodateFooter = function() {
var footerHeight = $('footer').outerHeight();
$(this).css({
'padding-bottom': footerHeight + 'px'
});
}
$('footer').on('DOMSubtreeModified', function() {
$('body').accomodateFooter();
})
$(window).on('resize', function() {
$('body').accomodateFooter();
})
$('body').accomodateFooter();
window.addMoreContentToFooter = function() {
var f = $('footer');
f.append($('<p />', {
text: "Human give me attention meow flop over sun bathe licks your face wake up wander around the house making large amounts of noise jump on top of your human's bed and fall asleep again. Throwup on your pillow sun bathe. The dog smells bad jump around on couch, meow constantly until given food, so nap all day, yet hiss at vacuum cleaner."
}))
.append($('<hr />'));
}
});
body {
min-height: 100vh;
position: relative;
}
footer {
background-color: rgba(0, 0, 0, .65);
color: white;
position: absolute;
bottom: 0;
width: 100%;
padding: 1.5rem;
display: block;
}
footer hr {
border-top: 1px solid rgba(0, 0, 0, .42);
border-bottom: 1px solid rgba(255, 255, 255, .21);
}
<link href="http://v4-alpha.getbootstrap.com/dist/css/bootstrap.min.css" rel="stylesheet">
<link href="http://v4-alpha.getbootstrap.com/examples/starter-template/starter-template.css" rel="stylesheet">
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.0.0/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/tether/1.2.0/js/tether.min.js"></script>
<script src="http://v4-alpha.getbootstrap.com/dist/js/bootstrap.min.js"></script>
<nav class="navbar navbar-toggleable-md navbar-inverse bg-inverse fixed-top">
<button class="navbar-toggler navbar-toggler-right" 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>
<a class="navbar-brand" href="#">Navbar</a>
<div class="collapse navbar-collapse" id="navbarsExampleDefault">
<ul class="navbar-nav mr-auto">
<li class="nav-item active">
<a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Link</a>
</li>
<li class="nav-item">
<a class="nav-link disabled" href="#">Disabled</a>
</li>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="http://example.com" id="dropdown01" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Dropdown</a>
<div class="dropdown-menu" aria-labelledby="dropdown01">
<a class="dropdown-item" href="#">Action</a>
<a class="dropdown-item" href="#">Another action</a>
<a class="dropdown-item" href="#">Something else here</a>
</div>
</li>
</ul>
<form class="form-inline my-2 my-lg-0">
<input class="form-control mr-sm-2" type="text" placeholder="Search">
<button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
</form>
</div>
</nav>
<div class="container">
<div class="starter-template">
<h1>Feed that footer - not a game (yet!)</h1>
<p class="lead">You will notice the body bottom padding is growing to accomodate the height of the footer as you feed it (so the page contents do not get covered by it).</p><button class="btn btn-warning" onclick="window.addMoreContentToFooter()">Feed that footer</button>
<hr />
<blockquote class="lead"><strong>Note:</strong> I used jQuery <code>v3.0.0</code> and Bootstrap <code>v4-alpha</code> but there is no reason why it shouldn't work with lower versions of each.</blockquote>
</div>
</div>
<footer>I am a footer with dynamic content.
<hr />
</footer>
Awalnya, saya telah memposting solusi ini di sini tetapi saya menyadari ini mungkin membantu lebih banyak orang jika diposting di bawah pertanyaan ini.
Catatan: Saya telah sengaja membungkus $([selector]).accomodateFooter()sebagai plugin jQuery, sehingga bisa dijalankan pada setiap elemen DOM, seperti di sebagian besar layout itu bukan $('body')'s bottom-paddingbahwa kebutuhan menyesuaikan, tetapi beberapa halaman wrapper elemen dengan position:relative(biasanya induk langsung dari footer) .
Sunting nanti (3+ tahun setelah jawaban awal):
Pada titik ini saya tidak lagi menganggap dapat diterima menggunakan JavaScript untuk memposisikan footer konten dinamis di bagian bawah halaman. Itu dapat dicapai dengan CSS saja, menggunakan flexbox, cepat, lintas-browser.
Ini dia:
// Left this in so you could inject content into the footer and test it:
// (but it's no longer sizing the footer)
function addMoreContentToFooter() {
var f = $('footer');
f.append($('<p />', {
text: "Human give me attention meow flop over sun bathe licks your face wake up wander around the house making large amounts of noise jump on top of your human's bed and fall asleep again. Throwup on your pillow sun bathe. The dog smells bad jump around on couch, meow constantly until given food, so nap all day, yet hiss at vacuum cleaner."
}))
.append($('<hr />'));
}
.wrapper {
min-height: 100vh;
padding-top: 54px;
display: flex;
flex-direction: column;
}
.wrapper>* {
flex-grow: 0;
}
.wrapper>main {
flex-grow: 1;
}
footer {
background-color: rgba(0, 0, 0, .65);
color: white;
width: 100%;
padding: 1.5rem;
}
footer hr {
border-top: 1px solid rgba(0, 0, 0, .42);
border-bottom: 1px solid rgba(255, 255, 255, .21);
}
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" integrity="sha384-Vkoo8x4CGsO3+Hhxv8T/Q5PaXtkKtu6ug5TOeNV6gBiFeWPGFN9MuhOf23Q9Ifjh" crossorigin="anonymous">
<script src="https://code.jquery.com/jquery-3.4.1.slim.min.js" integrity="sha384-J6qa4849blE2+poT4WnyKhv5vZF5SrPo0iEjwBvKU7imGFAV0wwj1yYfoRSJoZ+n" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js" integrity="sha384-Q6E9RHvbIyZFJoft+2mJbHaEWldlvI9IOYy5n3zV9zzTtmI3UksdQRVvoxMfooAo" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js" integrity="sha384-wfSDF2E50Y2D1uUdj0O3uMBJnjuUD4Ih7YwaYd1iqfktj0Uod8GCExl3Og8ifwB6" crossorigin="anonymous"></script>
<div class="wrapper">
<nav class="navbar navbar-expand-lg navbar-light bg-light fixed-top">
<a class="navbar-brand" href="#">Navbar</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarSupportedContent">
<ul class="navbar-nav mr-auto">
<li class="nav-item active">
<a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Link</a>
</li>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Dropdown
</a>
<div class="dropdown-menu" aria-labelledby="navbarDropdown">
<a class="dropdown-item" href="#">Action</a>
<a class="dropdown-item" href="#">Another action</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">Something else here</a>
</div>
</li>
<li class="nav-item">
<a class="nav-link disabled" href="#" tabindex="-1" aria-disabled="true">Disabled</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-outline-success my-2 my-sm-0" type="submit">Search</button>
</form>
</div>
</nav>
<main>
<div class="container">
<div class="starter-template">
<h1>Feed that footer - not a game (yet!)</h1>
<p class="lead">Footer won't ever cover the body contents, as its not fixed. It's simply placed at the bottom when the page should be shorter using `min-height:100vh` on container and using flexbox to push it down.</p><button class="btn btn-warning" onclick="addMoreContentToFooter()">Feed that footer</button>
<hr />
<blockquote class="lead">
<strong>Note:</strong> This example uses current latest versions of jQuery (<code>3.4.1.slim</code>) and Bootstrap (<code>4.4.1</code>) (unlike the one above).
</blockquote>
</div>
</div>
</main>
<footer>I am a footer with dynamic content.
<hr />
</footer>
</div>