方法一：通过增加100%高度行内块居中对齐
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title></title>
<style type="text/css">
div{
width: 600px;
height: 220px;
text-align: center;
border: 1px solid red;
} span{
height: 100%;
display: inline-block;
vertical-align: middle;
} img{
vertical-align: middle;
}
</style>
</head>
<body>
<div>
<span></span><img src="demo.jpg">
</div>
</body>
</html>
方法二：通过table/table-cell样式居中
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="viewport" content="width=device-width" />
<title></title>
<style type="text/css">
div{
width: 600px;
height: 220px;
text-align: center;
border: 1px solid red;
display: table;
} span{
display: table-cell;
vertical-align: middle;
} img{
vertical-align: middle;
}
</style>
</head>
<body>
<div class="container">
<span><img src="demo.jpg"></span>
</div>
</body>
</html>
方法三：设置为背景图片居中
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="viewport" content="width=device-width" />
<title></title>
<style type="text/css">
div{
width: 600px;
height: 220px;
text-align: center;
border: 1px solid red;
background-image: url('demo.jpg');
background-repeat: no-repeat;
background-position: center;
}
</style>
</head>
<body>
<div>
</div>
</body>
</html>