我正在尝试使用 Bootstrap 制作登录页面。到目前为止一切顺利，问题是垂直对齐。我想让登录表单贴在页面中央，所以我尝试阅读所有其他已回答的问题并尝试了很多不同的解决方案，但无济于事。我的代码如下。
.container {
display: table;
table-layout: fixed;
}
.form-horizontal {
width: 500px;
display: table-cell;
vertical-align: middle;
text-align: center;
}<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap-theme.min.css" integrity="sha384-rHyoN1iRsVXV4nD0JutlnGaslCJuC7uwjduW9SVrLvRYooPp2bWYgmgJQIXwl/Sp" crossorigin="anonymous">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js" integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa" crossorigin="anonymous"></script>
<link href="site_index.css" type="text/css" rel="stylesheet">
</head>
<body>
<div class="container">
<form class="form-horizontal">
<div class="form-group">
<label for="username" class="col-sm-2 control-label">Username</label>
<div class="col-sm-10">
<input type="email" class="form-control" id="username" placeholder="username" size="16">
</div>
</div>
<div class="form-group">
<label for="password" class="col-sm-2 control-label">Password</label>
<div class="col-sm-10">
<input type="password" class="form-control" id="password" placeholder="password" size="16">
</div>
</div>
<div class="form-group">
<div class="col-sm-offset-2 col-sm-10">
<button type="submit" class="btn btn-primary btn-lg btn-block" id="signin_button" value="Sign In">Sign in</button>
</div>
</div>
</form>
</div>
<footer id="w3c">
<hr>
<p>
Results and page (C) Copyright NerdLuv Inc.
</p>
<a href="http://validator.w3.org/check/referer">
<img src="http://www.cs.washington.edu/education/courses/cse190m/12sp/homework/4/w3c-html.png" alt="Valid HTML">
</a>
<a href="http://jigsaw.w3.org/css-validator/check/referer">
<img src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS">
</a>
</footer>最佳答案
有点hack，但我会想办法把它准确地放在中心。
只是尝试包裹盒子(.centerit)并移动它的位置。
.container {
display: table;
table-layout: fixed;
}
.form-horizontal {
width: 500px;
display: table-cell;
vertical-align: middle;
text-align: center;
}
#outer{
height:800px;
border:2px solid orange;
}
.centerit{
border:3px solid purple;
top:30%;
position:relative;
}<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<div id="outer">
<div class="centerit">
<div class="container">
<form class="form-horizontal">
<div class="form-group">
<label for="username" class="col-sm-2 control-label">Username</label>
<div class="col-sm-10">
<input type="email" class="form-control" id="username" placeholder="username" size="16">
</div>
</div>
<div class="form-group">
<label for="password" class="col-sm-2 control-label">Password</label>
<div class="col-sm-10">
<input type="password" class="form-control" id="password" placeholder="password" size="16">
</div>
</div>
<div class="form-group">
<div class="col-sm-offset-2 col-sm-10">
<button type="submit" class="btn btn-primary btn-lg btn-block" id="signin_button" value="Sign In">Sign in</button>
</div>
</div>
</form>
</div>
<footer id="w3c">
<hr>
<p>
Results and page (C) Copyright NerdLuv Inc.
</p>
<a href="http://validator.w3.org/check/referer">
<img src="http://www.cs.washington.edu/education/courses/cse190m/12sp/homework/4/w3c-html.png" alt="Valid HTML">
</a>
<a href="http://jigsaw.w3.org/css-validator/check/referer">
<img src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS">
</a>
</footer>
</div>
</div>关于html - 如何使用 Bootstrap 垂直对齐表单？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/48349014/