text-align CSS属性定义行内内容（例如文字）如何相对它的块父元素对齐。text-align 并不控制块元素自己的对齐，只控制它的行内内容的对齐。
/* Keyword values */ text-align: left; text-align: right; text-align: center; text-align: justify; text-align: justify-all; text-align: start; text-align: end; text-align: match-parent; /* Block alignment values (Non-standard syntax) */ text-align: -moz-center; text-align: -webkit-center; /* Global values */ text-align: inherit; text-align: initial; text-align: unset;
<div class="grid"> <div class="col"> <div class="row"> <div class="cell"> left <p class="taLeft">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pellen tesque vehicu la con vallis.</p> </div> <div class="cell"> start (ltr) <p class="taStart ltr">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pellen tesque vehicu la con vallis.</p> </div> <div class="cell"> start (rtl) <p class="taStart rtl">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pellen tesque vehicu la con vallis.</p> </div> </div> <div class="row"> <div class="cell"> right <p class="taRight">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pellen tesque vehicu la con vallis.</p> </div> <div class="cell"> end (ltr) <p class="taEnd ltr">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pellen tesque vehicu la con vallis.</p> </div> <div class="cell"> end (rtl) <p class="taEnd rtl">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pellen tesque vehicu la con vallis.</p> </div> </div> <div class="row"> <div class="cell"> center <p class="taCenter">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pellen tesque vehicu la con vallis.</p> </div> <div class="cell"> justify <p class="taJustify">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pellen tesque vehicu la con vallis.</p> </div> <div class="cell"> justify-all <p class="taJustifyAll">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pellen tesque vehicu la con vallis.</p> </div> </div> </div> </div>
html,body {
height: 100%;
box-sizing: border-box;
}
.grid {
width: 100%;
height: 100%;
display: flex;
background: #EEE;
font: 1em monospace;
}
.row {
display: flex;
flex: 1 auto;
flex-direction: row;
}
.col {
display: flex;
flex: 1 auto;
flex-direction: column;
}
.cell {
width: calc(33.33% - 1em);
box-sizing: border-box;
margin: .5em;
padding: .5em;
background-color: #FFF;
overflow: hidden;
}
@media (max-width: 30em) {
.row {
flex-direction: column;
}
}
p {
font: .8em sans-serif;
max-width: 100%;
box-sizing: border-box;
overflow: hidden;
resize: horizontal;
background: #E4F0F5;
padding: .5em;
margin: .5em 0 0;
}
.taLeft { text-align: left; }
.taRight { text-align: right; }
.taCenter { text-align: center; }
.taJustify { text-align: justify; }
.taJustifyAll { text-align: justify-all; }
.taStart { text-align: start; }
.taEnd { text-align: end; }
.rtl { direction: rtl; }
.ltr { direction: ltr; }
| 初始值 | start, or a nameless value that acts as left if direction is ltr, right if direction is rtl if start is not supported by the browser. |
|---|---|
| 适用元素 | block containers |
| 是否是继承属性 | yes |
| 适用媒体 | visual |
| 计算值 | as specified, except for the match-parent value which is calculated against its parent's direction value and results in a computed value of either left or right |
| Animation type | discrete |
| 正规顺序 | order of appearance in the formal grammar of the values |
语法
text-align属性指定为从以下值列表中选择的单个关键字。
Values
start- 如果内容方向是左至右，则等于
left，反之则为right。 end- 如果内容方向是左至右，则等于righ
t，反之则为left。 left- 行内内容向左侧边对齐。
right- 行内内容向右侧边对齐。
center- 行内内容居中。
<string>- 第一个出现的该（单字符）字符串被用来对齐。跟随的关键字定义对齐的方向。例如，可用于让数字值根据小数点对齐。
justify- 文字向两侧对齐，对最后一行无效。
justify-all- 和justify一致，但是强制使最后一行两端对齐。
match-parent和inherit类似，区别在于start和end的值根据父元素的direction确定，并被替换为恰当的left或right。
指示语法
start | end | left | right | center | justify | match-parent
示例
Live Examples
div { text-align: center; border:solid; }
p { background:gold; width:22em; }
some more inline content...div { text-align: center; border:solid; }
p { background:gold; width:22em; margin: 1em auto; }
some more inline content...div { text-align:-moz-center; text-align:-webkit-center; border:solid; }
p { background:gold; width:22em; }
some more inline content...备注
居中一个块元素且不居中它的行内内容的标准兼容的方法是将它的左、右margin设为auto, 例如：
margin:auto; 或margin:0 auto; 或margin-left:auto; margin-right:auto;
示例
Left alignment
HTML
<p class="example">
Integer elementum massa at nulla placerat varius.
Suspendisse in libero risus, in interdum massa.
Vestibulum ac leo vitae metus faucibus gravida ac in neque.
Nullam est eros, suscipit sed dictum quis, accumsan a ligula.
</p>CSS
.example {
text-align: left;
border: solid;
}Result
Centered text
HTML
<p class="example">
Integer elementum massa at nulla placerat varius.
Suspendisse in libero risus, in interdum massa.
Vestibulum ac leo vitae metus faucibus gravida ac in neque.
Nullam est eros, suscipit sed dictum quis, accumsan a ligula.
</p>CSS
.example {
text-align: center;
border: solid;
}Result
Justify
HTML
<p class="example">
Integer elementum massa at nulla placerat varius.
Suspendisse in libero risus, in interdum massa.
Vestibulum ac leo vitae metus faucibus gravida ac in neque.
Nullam est eros, suscipit sed dictum quis, accumsan a ligula.
</p>CSS
.example {
text-align: justify;
border: solid;
}Result
Notes
The standard-compatible way to center a block itself without centering its inline content is setting the left and right margin to auto, e.g.:
.something {
margin: auto;
}.something {
margin: 0 auto;
}.something {
margin-left: auto;
margin-right: auto;
}规范
| 规范 | 状态 | 备注 |
|---|---|---|
| CSS Text Module Level 3 visibility |
Working Draft | 添加了start和end关键字 keyword. Changed the unnamed initial value to start (which it was). Added the <string> value, the match-parent value and the start end double value. |
| CSS Level 2 (Revision 1) text-align |
Recommendation | 无改变 |
| CSS Level 1 text-align |
Recommendation | 首次定义 |
浏览器兼容性
We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!
| Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|---|
Basic support (left, right, center and justify) |
1.0 | (Yes) | 1.0 (1.7 or earlier) | 3.0 | 3.5 | 1.0 (85) |
| Block alignment values | 1.0-webkit | ? | 1.0 (1.7 or earlier)-moz[1] | 未实现 | 未实现 | 1.0 (85)-khtml 1.3 (312)-webkit [1] |
start |
1.0 | ? | 1.0 (1.7 or earlier) | 未实现 | (Yes) | 3.1 (525) |
end |
1.0 | ? | 3.6 (1.9.2) | 未实现 | (Yes) | 3.1 (525) |
match-parent |
16 | ? | 40 (40) | 未实现 | 未实现 | 未实现 |
| Feature | Android | Chrome for Android | Edge | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|---|
| Basic support | ? | ? | (Yes) | ? | ? | ? | ? |
| Block alignment values | ? | ? | ? | ? | ? | ? | ? |
start |
? | ? | ? | ? | ? | ? | ? |
end |
? | ? | ? | ? | ? | ? | ? |
match-parent |
? | ? | ? | 40.0 (40) | ? | ? | ? |
true(non-standard syntax) |
未实现 | 未实现 | ? | ? | 未实现 |
[1] Both WebKit and Gecko supports a prefixed version of left, center, and right, that applies not only to inline content but also to block elements. This is used to implement the legacy align attributes on some table-related element. Do not use these on production Web sites.