如何在 Bootstrap 4 中垂直对齐表单答案

【问题标题】：How to vertically align a form in Bootstrap 4如何在 Bootstrap 4 中垂直对齐表单
【发布时间】：2017-11-03 06:21:03
【问题描述】：

我在容器div 中有一个表单，我希望在页面中垂直对齐它。我无法为我的生活弄清楚如何。我尝试使用表格等以及弹性框，但我无法理解它。

这是我的代码

<!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 http-equiv="x-ua-compatible" content="ie-edge">

    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/css/bootstrap.min.css" integrity="sha384-rwoIResjU2yc3z8GV/NPeZWAv56rSmLldC3R/AZzGRnGxQQKnKkoFVhFQhNUwEyJ" crossorigin="anonymous">
    <link rel="stylesheet" href="login.css" type="text/css">


  </head>

   <body>

    <div class="container">
       <div class="alert alert-warning alert dismissable fade show" role="alert">
          <button type="button" class="close" data-dismiss="alert" aria-label="close"><span aria-hidden="true">&times;</span></button>
           <strong>Note:</strong> This feature is not working yet. Don't try to log in!
        </div>
        <form class="form-signin  col-6 align-self-center">
            <h1 class="text-center">Sign In!</h1>
            <p>
                <label class="sr-only">Email Address</label>
                <input type="emai" placeholder="Email Address" class="form-control" required autofocus>
            </p>
            <p>
                <label class="sr-only">Password</label>
                <input type="password" placeholder="Password" class="form-control" required autofocus>
            </p>

            <p class="checkbox"><label><input type="checkbox"> Remember me</label></p>

            <button type="submit" class="btn btn-primary btn-block ">Sign in</button>
        </form>

    </div>


    <script src="https://code.jquery.com/jquery-3.1.1.slim.min.js" integrity="sha384-A7FZj7v+d/sdmMqp/nOQwliLvUsJfDHW+k9Omg/a/EheAdgtzNs3hpfag6Ed950n" crossorigin="anonymous"></script>

    <script src="https://cdnjs.cloudflare.com/ajax/libs/tether/1.4.0/js/tether.min.js" integrity="sha384-DztdAPBWPRXSA/3eYEEUWrWCy7G5KFbe8fFjk5JAIxUYHKkDx6Qin1DkWx51bBrb" crossorigin="anonymous"></script>

    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/js/bootstrap.min.js" integrity="sha384-vBWWzlZJ8ea9aCX4pEW3rVHjgjt7zpkNpZk+02D9phzyeVkE+jo0ieGizqPLForn" crossorigin="anonymous"></script>

  </body>

</html>

And here is the CSS

    html, body {

    height: 100%;

}

.container {

    max-width: 400px;
    height: 100%;
    min-height: 100%;


}

.form-signin {

    vertical-align: middle;
}

.box {

    border: 1px red dotted;
}

【问题讨论】：

检查小提琴jsfiddle.net/gkzhtknv

标签： forms twitter-bootstrap alignment

【解决方案1】：

将height: 100% 添加到 div 元素不会将其拉伸到整个屏幕。您可以通过向您的 div 添加一些边框来检查这一点。因此，将 .container 类中的高度值更改为 100vh 应该可以解决您的问题。

【讨论】：