我使用了这段非常简单的代码:

Div.ext-box{显示:表;宽度:100%;} Div.int-box{显示:表单元;vertical-align:中间;｝ < div class = " ext-box”> < div class = " int-box”> 一些txt < h2 > < / h2 > <p>bla bla bla</p> < / div > < / div >

显然，无论您使用.class还是#id，结果都不会改变。

下面是另一种(响应性的)方法:

html,
    body {
        height: 100%;
    }
    body {
        margin: 0;
    }

    .table {
        display: table;
        width:  auto;
        table-layout:auto;
        height: 100%;
    }
        .table:nth-child(even) {
            background: #a9edc3;
        }
        .table:nth-child(odd) {
            background: #eda9ce;
        }

    .tr {
        display: table-row;
    }
    .td {
        display: table-cell;
        width: 50%;
        vertical-align: middle;
    }

http://jsfiddle.net/herrfischerhamburg/JcVxz/

我的技巧是在div里面放一个表，一行一列，设置100%的宽度和高度，属性vertical-align:middle:

<div>

    <table style="width:100%; height:100%;">
        <tr>
            <td style="vertical-align:middle;">
                BUTTON TEXT
            </td>
        </tr>
    </table>

</div>

小提琴: http://jsfiddle.net/joan16v/sbqjnn9q/

垂直和水平对齐元素

使用它们中的任何一个。结果是一样的:

引导4 CSS3

1. 引导4.3 +

垂直对齐:d-flex align-items-center

水平对齐:d-flex justify-content-center

垂直和水平对齐:d-flex align-items-center justify-content-center

.container { 身高:180 px; 宽度:100%; background - color: blueviolet; ｝ .container > div { 背景颜色:白色; 填充:1快速眼动; ｝ <链接的href = " https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css " rel = "样式表" / > <div class="d-flex align-items-center - align- content-center container"> <div>我在中心</div> < / div >

2. CSS 3

.container { 身高:180 px; 宽度:100%; background - color: blueviolet; ｝ .container > div { 背景颜色:白色; 填充:1快速眼动; ｝ .center { 显示:flex; 对齐项目:中心; justify-content:中心; ｝ <div class="集装箱中心"> <div>我在中心</div> < / div >

哇，这个问题很受欢迎。这是基于对垂直对齐属性的误解。这篇优秀的文章解释了这一点:

理解垂直对齐，或者Gavin Kistner的“如何(不)垂直居中内容”。

“如何在CSS中居中”是一个很好的网络工具，它可以帮助您在不同的情况下找到必要的CSS居中属性。

简而言之(并防止链接腐烂):

Inline elements (and only inline elements) can be vertically aligned in their context via vertical-align: middle. However, the “context” isn’t the whole parent container height, it’s the height of the text line they’re in. jsfiddle example For block elements, vertical alignment is harder and strongly depends on the specific situation: If the inner element can have a fixed height, you can make its position absolute and specify its height, margin-top and top position. jsfiddle example If the centered element consists of a single line and its parent height is fixed you can simply set the container’s line-height to fill its height. This method is quite versatile in my experience. jsfiddle example … there are more such special cases.

我使用了这段非常简单的代码:

Div.ext-box{显示:表;宽度:100%;} Div.int-box{显示:表单元;vertical-align:中间;｝ < div class = " ext-box”> < div class = " int-box”> 一些txt < h2 > < / h2 > <p>bla bla bla</p> < / div > < / div >

显然，无论您使用.class还是#id，结果都不会改变。