DIV+CSS布局中的居中问题
1、DIV居中
body {text-align: center;}
div {margin-right: auto; margin-left: auto;}
说明：对于IE，在父元素定义“text-align: center;”就可以了对于FF等其他浏览器，仅这样不能居中，需在子元素中定义“margin-right: auto; margin-left: auto;”。
2、背景居中
body {background:url(#) #fff no-repeat center;}
说明：参数中的center是对背景位置的定义。
3、文本垂直居中
div {vertical-align:middle;line-height:？px;}
说明：vertical-align:middle;表示行内垂直居中，我们将行距调整到和整个DIV一样高，文字就垂直居中了。
下面是几个例子：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>div里面图片垂直居中的几个例子</title>
<style type="text/css">
<!--
* {margin:0;padding:0}
div {
width:500px;
height:500px;
border:1px solid #666;
overflow:hidden;
position:relative;
display:table-cell;
text-align:center;
vertical-align:middle
}
div p {
position:static;
+position:absolute;
top:50%
}
img {
position:static;
+position:relative;
top:-50%;left:-50%;
}
-->
</style>
</head>
<body>
<div><p><img src="http://www.google.com/intl/en/images/logo.gif" /></p></div>
</body>
</html>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>div里面图片垂直居中的几个例子</title>
<style type="text/css">
<!--
body {
margin:0;padding:0
}
div {
width:500px;
height:500px;
line-height:500px;
border:1px solid #666;
overflow:hidden;
position:relative;
text-align:center;
}
div p {
position:static;
+position:absolute;
top:50%
}
img {
position:static;
+position:relative;
top:-50%;left:-50%;
vertical-align:middle
}
p:after {
content:".";font-size:1px;
visibility:hidden
}
-->
</style>
</head>
<body>
<div><p><img src="http://www.google.com/intl/en/images/logo.gif" /></p></div>
</body>
</html>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>div里面图片垂直居中的几个例子</title>
<style type="text/css">
<!--
* {margin:0;padding:0}
div {
width:500px;
height:500px;
line-height:500px;
border:1px solid #666;
overflow:hidden;
position:relative;
text-align:center;
}
div p {
position:static;
+position:absolute;
top:50%;
vertical-align:middle
}
img {
position:static;
+position:relative;
top:-50%;left:-50%;
vertical-align:middle
}
-->
</style>
</head>
<body>
<div><p><img src="http://www.google.com/intl/en/images/logo.gif" /></p></div>
</body>
</html>
背景方式：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>div里面图片垂直居中的几个例子</title>
<style type="text/css">
<!--
* {margin:0;padding:0;}
div {
width:500px;border:1px solid #666;
height:500px;
background:url("http://www.google.com/intl/en/images/logo.gif") center no-repeat
}
-->
</style>
</head>
<body>
<div></div>
</body>
</html>
