我有一个页面,其中只有形式存在,我想把形式放在屏幕的中心。

<div class="container">
  <div class="row justify-content-center align-items-center">
    <form>
      <div class="form-group">
        <label for="formGroupExampleInput">Example label</label>
        <input type="text" class="form-control" id="formGroupExampleInput" placeholder="Example input">
      </div>
      <div class="form-group">
        <label for="formGroupExampleInput2">Another label</label>
        <input type="text" class="form-control" id="formGroupExampleInput2" placeholder="Another input">
      </div>
    </form>   
  </div>  
</div>

justify-content-center使表单水平对齐,但我不知道如何垂直对齐。我尝试使用align-items-center和align-self-center,但它不起作用。

我错过了什么?

DEMO


当前回答

Flexbox可以帮助您。信息在这里

<div class="d-flex flex-row justify-content-center align-items-center" style="height: 100px;">
    <div class="p-2">
     1
    </div>
    <div class="p-2">
     2
    </div>
</div>

其他回答

引导程序具有文本中心来集中文本。例如

<div class="container text-center">

您可以更改以下内容

<div class="row justify-content-center align-items-center">

到以下

<div class="row text-center">

<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" rel="stylesheet"/> <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <div class="col-12 border border-info"> <div class="d-flex justify-content-center align-items-center" style="height: 100px"> <a href="#" class="btn btn-dark">Transfer</a> <a href="#" class="btn btn-dark mr-2 ml-2">Replenish</a> <a href="#" class="btn btn-dark mr-3">Account Details</a> </div> </div>

从bootstrap v5.0开始:

<div class="position-absolute top-50 start-50 translate-middle">
   centred
</div>

引导5

body {
  display: flex;
  align-items: center;
}

https://getbootstrap.com/docs/5.1/examples/sign-in/

从文档(引导4):

https://getbootstrap.com/docs/4.0/utilities/flex/#justify-content

.justify-content-start
.justify-content-end
.justify-content-center
.justify-content-between
.justify-content-around
.justify-content-sm-start
.justify-content-sm-end
.justify-content-sm-center
.justify-content-sm-between
.justify-content-sm-around
.justify-content-md-start
.justify-content-md-end
.justify-content-md-center
.justify-content-md-between
.justify-content-md-around
.justify-content-lg-start
.justify-content-lg-end
.justify-content-lg-center
.justify-content-lg-between
.justify-content-lg-around
.justify-content-xl-start
.justify-content-xl-end
.justify-content-xl-center
.justify-content-xl-between
.justify-content-xl-around