CSS3/CSS之居中解析(水平+垂直居中、水平居中,垂直居中)
今天,博主带来的是CSS3/CSS中的居中解析,相信小伙伴们有时候也会被各种居中搞的一脸懵逼把!
居中总体来说可以分为水平居中还有垂直居中,正中央,顾名思义,定义这里就不解释了!
首先,我们来看下垂直居中:
(1)、如果是单行文本,则可以设置的line-height的数值,让其等于父级元素的高度!
<!DOCTYPE html
>
<
html
lang=
"en"
>
<
head
>
<
meta
charset=
"UTF-8"
>
<
meta
name=
"viewport"
content=
"width=device-width, initial-scale=1.0"
>
<
meta
http-equiv=
"X-UA-Compatible"
content=
"ie=edge"
>
<
title
>Document
</
title
>
<
style
>
.box{
background:
green;
height:
200px;
}
a {
height:
100%;
line-height:
200px;
color:
red;
}
<
/
style
>
</
head
>
<
body
>
<
div
class=
"box"
>
<
a
href=
""
>ggg
</
a
>
</
div
>
</
body
>
</
html
>
(2)、如果元素是行内块级元素,一般会使用diaplay:inline-block,vertical-align:middle,还有一个伪元素让元素内容处于容器中央!给父元素添加伪元素!
<!DOCTYPE html
>
<
html
lang=
"en"
>
<
head
>
<
meta
charset=
"UTF-8"
>
<
meta
name=
"viewport"
content=
"width=device-width, initial-scale=1.0"
>
<
meta
http-equiv=
"X-UA-Compatible"
content=
"ie=edge"
>
<
title
>Document
</
title
>
<
style
>
.box {
background:
green;
height:
200px;
}
.box::after, .box2{
display:
inline-block;
vertical-align:
middle;
}
.box::after{
content:
'';
height:
100%;
}
.box2{
background-color:
red;
width:
20px;
height:
20px;}
<
/
style
>
</
head
>
<
body
>
<
div
class=
"box"
>
<
div
class=
"box2"
></
div
>
</
div
>
</
body
>
</
html
>

(3)、通过display:flex来实现垂直居中;
父级:display:flex;
子元素:align-self:center;
<!DOCTYPE html
>
<
html
lang=
"en"
>
<
head
>
<
meta
charset=
"UTF-8"
>
<
meta
name=
"viewport"
content=
"width=device-width, initial-scale=1.0"
>
<
meta
http-equiv=
"X-UA-Compatible"
content=
"ie=edge"
>
<
title
>Document
</
title
>
<
style
>
.box {
background:
green;
height:
300px;
width:
600px;
display:
flex;
}
.box2{
background:
red;
width:
30%;
height:
30%;
align-self:
center;
}
<
/
style
>
</
head
>
<
body
>
<
div
class=
"box"
>
<
div
class=
"box2"
></
div
>
</
div
>
</
body
>
</
html
>
(4)、使用display:table进行垂直居中!
给父元素设置display:table;子元素设置为display:table-cell;