1、固定宽度width属性,将margin-left和margin-right设置为auto
div{
width:300px;
margin-left:auto;
marign-right:auto;
}
优点:简单易懂,兼容性强
缺点:扩展性差,对未知宽度属性的组件无法设置
2、将position属性设置为relative,父子块元素float都为同一方向,之后让父子块元素向相反方向各位移50%,即可达到居中目的
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" ></meta>
<title></title>
</head>
<style type="text/css">
.menu{
width: 95px;
height: 30px;
background: #FF0000;
color: #FFF;
float: left;
text-align: center;
margin-right: 10px;
padding-top: 12px;
border-spacing: 10px;
right: 50%;
position: relative;
}
#form{
width: auto;
height: 100px;
border-color: #FF0000;
border-width: thin;
border-style: solid;
left: 50%;
position: relative;
float: left;
}
</style>
<body>
<div id="form">
<div class="menu">首页</div>
<div class="menu">详情</div>
<div class="menu">管理</div>
<div class="menu">投诉</div>
<div class="menu">反馈</div>
<div class="menu">留言</div>
<div class="menu">举报</div>
<div class="menu">拉黑</div>
<div class="menu">点赞</div>
</div>
</body>
</html>
优点:兼容性强,扩展性强
缺点:操作略复杂