如果flex-container有多行(when，flex-wrap:wrap)，align-content属性定义容器中每一行的对齐方式.
用法 :
align-content: flex-start | flex-end | center | space-between | space-around
此属性接受以下值 :
拉伸 : 内容中的线条将拉伸以填满剩余空间.
flex-start : 内容中的所有行都打包在容器的开头.
flex-end : 内容中的所有行都打包在容器的末尾.
center : 内容中的所有行都打包在容器的中心.
space-between : 额外的空间均匀分布在线条之间.
space-around : 额外的空间在线之间均匀分布，每条线周围的空间相等(包括第一行和最后一行)
在将此值传递给属性 align-content 时，所有行都打包在容器的中心.
以下示例演示了将值 center 传递给的结果 align-content 属性.
<!doctype html>
<html lang = "en">
<style>
.box1{background:green;}
.box2{background:blue;}
.box3{background:red;}
.box4{background:magenta;}
.box5{background:yellow;}
.box6{background:pink;}
.box{
font-size:25px;
padding:15px;
width:43%;
}
.container{
display:flex;
height:100vh;
flex-wrap:wrap;
align-content:center;
}
</style>
<body>
<div class = "container">
<div class = "box box1">One</div>
<div class = "box box2">two</div>
<div class = "box box3">three</div>
<div class = "box box4">four</div>
<div class = "box box5">five</div>
<div class = "box box6">six</div>
</div>
</body>
</html>将此值传递给属性align-content时，所有行都在容器的开头打包。
以下示例演示将值flex-start传递给align-content属性的结果。
<!doctype html>
<html lang = "en">
<style>
.box1{background:green;}
.box2{background:blue;}
.box3{background:red;}
.box4{background:magenta;}
.box5{background:yellow;}
.box6{background:pink;}
.box{
font-size:25px;
padding:15px;
width:40%;
}
.container{
display:flex;
height:100vh;
flex-wrap:wrap;
align-content:flex-start;
}
</style>
<body>
<div class = "container">
<div class = "box box1">One</div>
<div class = "box box2">two</div>
<div class = "box box3">three</div>
<div class = "box box4">four</div>
<div class = "box box5">five</div>
<div class = "box box6">six</div>
</div>
</body>
</html>将此值传递给属性align-content时，所有行都打包在容器的末尾。
以下示例演示将值flex-end传递给align-content属性的结果。
<!doctype html>
<html lang = "en">
<style>
.box1{background:green;}
.box2{background:blue;}
.box3{background:red;}
.box4{background:magenta;}
.box5{background:yellow;}
.box6{background:pink;}
.box{
font-size:25px;
padding:15px;
width:40%;
}
.container{
display:flex;
height:100vh;
flex-wrap:wrap;
align-content:flex-end;
}
</style>
<body>
<div class = "container">
<div class = "box box1">One</div>
<div class = "box box2">two</div>
<div class = "box box3">three</div>
<div class = "box box4">four</div>
<div class = "box box5">five</div>
<div class = "box box6">six</div>
</div>
</body>
</html>将此值传递给属性align-content时，线条将拉伸以填充剩余空间。
以下示例演示将值stretch传递给align-content属性的结果。
<!doctype html>
<html lang = "en">
<style>
.box1{background:green;}
.box2{background:blue;}
.box3{background:red;}
.box4{background:magenta;}
.box5{background:yellow;}
.box6{background:pink;}
.box{
font-size:25px;
padding:15px;
width:40;
}
.container{
display:flex;
height:100vh;
flex-wrap:wrap;
align-content:stretch;
}
</style>
<body>
<div class = "container">
<div class = "box box1">One</div>
<div class = "box box2">two</div>
<div class = "box box3">three</div>
<div class = "box box4">four</div>
<div class = "box box5">five</div>
<div class = "box box6">six</div>
</div>
</body>
</html>在将此值传递给属性align-content时，额外空间在线之间均匀分布，每条线周围的空间相等（包括第一行和最后一行）。
以下示例演示了将值space-around传递给align-content属性的结果。
<!doctype html>
<html lang = "en">
<style>
.box1{background:green;}
.box2{background:blue;}
.box3{background:red;}
.box4{background:magenta;}
.box5{background:yellow;}
.box6{background:pink;}
.box{
font-size:25px;
padding:15px;
width:40%;
}
.container{
display:flex;
height:100vh;
flex-wrap:wrap;
align-content:space-around;
}
</style>
<body>
<div class = "container">
<div class = "box box1">One</div>
<div class = "box box2">two</div>
<div class = "box box3">three</div>
<div class = "box box4">four</div>
<div class = "box box5">five</div>
<div class = "box box6">six</div>
</div>
</body>
</html>在将此值传递给属性align-content时，额外空间将均匀地分布在行之间，其中第一行将位于顶部，最后一行将位于容器的底部。
以下示例演示了将值space-between传递给align-content属性的结果。
<!doctype html>
<html lang = "en">
<style>
.box1{background:green;}
.box2{background:blue;}
.box3{background:red;}
.box4{background:magenta;}
.box5{background:yellow;}
.box6{background:pink;}
.box{
font-size:25px;
padding:15px;
width:40%;
}
.container{
display:flex;
height:100vh;
flex-wrap:wrap;
align-content:space-between;
}
</style>
<body>
<div class = "container">
<div class = "box box1">One</div>
<div class = "box box2">two</div>
<div class = "box box3">three</div>
<div class = "box box4">four</div>
<div class = "box box5">five</div>
<div class = "box box6">six</div>
</div>
</body>
</html>
