如何使元素水平和垂直居中-前端问题

How to center an element horizontally and vertically(如何使元素水平和垂直居中)

本文介绍了如何使元素水平和垂直居中的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我试图将标签内容垂直居中，但是当我添加 CSS 样式 display:inline-flex 时，水平文本对齐消失了.

I am trying to center my tabs content vertically, but when I add the CSS style display:inline-flex, the horizontal text-align disappears.

如何为每个选项卡设置 x 和 y 文本对齐方式?

How can I make both text alignments x and y for each of my tabs?

* { box-sizing: border-box; }
#leftFrame {
  background-color: green;
  position: absolute;
  left: 0;
  right: 60%;
  top: 0;
  bottom: 0;
}
#leftFrame #tabs {
  background-color: red;
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 25%;
}
#leftFrame #tabs div {
  border: 2px solid black;
  position: static;
  float: left;
  width: 50%;
  height: 100%;
  text-align: center;
  display: inline-flex;
  align-items: center;
}

<div id=leftFrame>
  <div id=tabs>
    <div>first</div>
    <div>second</div>
  </div>
</div>

推荐答案

方法一 - transform translateX/translateY:
此处示例/全屏示例

在支持的浏览器(大部分)中，可以使用top: 50%/left: 50% 结合 translateX(-50%) translateY(-50%) 动态地垂直/水平居中元素.

In supported browsers (most of them), you can use top: 50%/left: 50% in combination with translateX(-50%) translateY(-50%) to dynamically vertically/horizontally center the element.
```
.container {
    position: absolute;
    top: 50%;
    left: 50%;
    -moz-transform: translateX(-50%) translateY(-50%);
    -webkit-transform: translateX(-50%) translateY(-50%);
    transform: translateX(-50%) translateY(-50%);
}
```
```
<div class="container">
    <span>I'm vertically/horizontally centered!</span>
</div>
```
- 方法 2 - Flexbox 方法:
  此处示例/全屏示例
在支持的浏览器中，将目标元素的display设置为flex 并使用 align-items: center 进行垂直居中，使用 justify-content: center 进行水平居中.只是不要忘记添加供应商前缀以获得额外的浏览器支持(查看示例).

In supported browsers, set the display of the targeted element to flex and use align-items: center for vertical centering and justify-content: center for horizontal centering. Just don't forget to add vendor prefixes for additional browser support (see example).
```
html, body, .container {
    height: 100%;
}

.container {
    display: -webkit-flexbox;
    display: -ms-flexbox;
    display: -webkit-flex;
    display: flex;
    -webkit-flex-align: center;
    -ms-flex-align: center;
    -webkit-align-items: center;
    align-items: center;
    justify-content: center;
}
```
```
<div class="container"> 
  <span>I'm vertically/horizontally centered!</span>
</div>
```
- 方法3 - table-cell/vertical-align: middle:
  此处示例/全屏示例
在某些情况下，您需要确保 html/body 元素的高度设置为 100%.

In some cases, you will need to ensure that the html/body element's height is set to 100%.

对于垂直对齐，将父元素的width/height设置为100%并添加display:table.然后对于子元素，将 display 更改为 table-cell 并添加 vertical-align: middle.

For vertical alignment, set the parent element's width/height to 100% and add display: table. Then for the child element, change the display to table-cell and add vertical-align: middle.

对于水平居中，您可以添加 text-align: center 以使文本和任何其他 inline 子元素居中.或者，您可以使用 margin: 0 auto，假设元素是 block 级别.

For horizontal centering, you could either add text-align: center to center the text and any other inline children elements. Alternatively, you could use margin: 0 auto, assuming the element is block level.
```
html, body {
    height: 100%;
}
.parent {
    width: 100%;
    height: 100%;
    display: table;
    text-align: center;
}
.parent > .child {
    display: table-cell;
    vertical-align: middle;
}
```
```
<section class="parent">
    <div class="child">I'm vertically/horizontally centered!</div>
</section>
```
- 方法 4 - 绝对定位 50% 距离顶部有位移:
  此处示例/全屏示例
- Approach 4 - Absolutely positioned 50% from the top with displacement:
  
  Example Here / Full Screen Example
此方法假定文本具有已知高度 - 在本例中为 18px.相对于父元素，从顶部绝对定位元素 50%.使用一个负的 margin-top 值，该值是元素已知高度的一半，在本例中为 -9px.

This approach assumes that the text has a known height - in this instance, 18px. Just absolutely position the element 50% from the top, relative to the parent element. Use a negative margin-top value that is half of the element's known height, in this case - -9px.
```
html, body, .container {
    height: 100%;
}

.container {
    position: relative;
    text-align: center;
}

.container > p {
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    margin-top: -9px;
}
```
```
<div class="container">
    <p>I'm vertically/horizontally centered!</p>
</div>
```
- 方法 5 - line-height 方法(最不灵活 - 不建议):
  此处示例
- Approach 5 - The line-height method (Least flexible - not suggested):
  
  Example Here
在某些情况下，父元素会有一个固定的高度.对于垂直居中，您所要做的就是在子元素上设置一个 line-height 值，使其等于父元素的固定高度.

In some cases, the parent element will have a fixed height. For vertical centering, all you have to do is set a line-height value on the child element equal to the fixed height of the parent element.

虽然此解决方案在某些情况下会起作用，但值得注意的是，当有多行文本时它不起作用 - 像这样.

Though this solution will work in some cases, it's worth noting that it won't work when there are multiple lines of text - like this.
```
.parent {
    height: 200px;
    width: 400px;
    background: lightgray;
    text-align: center;
}

.parent > .child {
    line-height: 200px;
}
```
```
<div class="parent">
    <span class="child">I'm vertically/horizontally centered!</span>
</div>
```
这篇关于如何使元素水平和垂直居中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！