本文实例讲述了jQuery实现的浮动层div浏览器居中显示效果。分享给大家供大家参考，具体如下：
1.在页面的head中引入jQuery
<script type="text/javascript" language="javascript" src="jquery-1.7.2.min.js"></script>
2.在页面的head中加入浮动层和遮罩层的样式
<style>#previewDiv{z-index: 9999;position:absolute;display:none;background:#fff;border-top:5px solid #999;border-bottom:7px solid #999;border-left:5px solid #999;border-right:7px solid #999;}.mask {color:#C7EDCC;background-color:#999;position:absolute;top:0px;left:0px;width:100%;height:3000px;opacity: 0.6;filter: "alpha(opacity=60)";filter: alpha(Opacity=60);}</style>3.在页面的底部加上浮动的div
<div id="previewDiv"> <table id ="head"> <tr><td>短消息预览</td></tr> </table> <table align="center"> <tr><td> <div class="zhnx_neirong"> <h3>您收到了来自脚本之家的回复</h3> <p class="duanluo"> 内容：这是浮动层居中的实例</span></p> </div> </td></tr> </table> <table align="center"> <tr><td><div><input type="button" value=" 关 闭 " onclick="hide();"/></div></td></tr> </table></div>4.添加显示和隐藏的js函数
function show(){ //添加并显示遮罩层 $("<div id='mask'></div>").addClass("mask").click(function() {}) .appendTo("body").fadeIn(0); document.getElementById("mask").style.display = "block"; var windowWidth = document.documentElement.clientWidth; var windowHeight = document.documentElement.clientHeight; var popupHeight = $("#previewDiv").height(); var popupWidth = $("#previewDiv").width(); $("#previewDiv").css({ "position": "absolute", "top": (windowHeight-popupHeight)/2+$(document).scrollTop(), "left": (windowWidth-popupWidth)/2 }); $("#previewDiv").show();}function hide(){ $("#mask").remove(); $("#previewDiv").hide();}完整实例代码如下：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"<head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>Test</title><script type="text/javascript" language="javascript" src="jquery-1.7.2.min.js"></script></head><body><style>#previewDiv{z-index: 9999;position:absolute;display:none;background:#fff;border-top:5px solid #999;border-bottom:7px solid #999;border-left:5px solid #999;border-right:7px solid #999;}.mask {color:#C7EDCC;position:absolute;top:0px;left:0px;100%;height:3000px;opacity: 0.6;filter: "alpha(opacity=60)";filter: alpha(Opacity=60);}</style><div id="previewDiv"> <table id ="head"> <tr><td>短消息预览</td></tr> </table> <table align="center"> <tr><td> <div class="zhnx_neirong"> <h3>您收到了来自脚本之家的回复</h3> <p class="duanluo"> 内容：这是浮动层居中的实例</span></p> </div> </td></tr> </table> <table align="center"> <tr><td><div><input type="button" value=" 关 闭 " onclick="hide();"/></div></td></tr> </table></div><script type="text/javascript" language="javascript" > function show(){ //添加并显示遮罩层 $("<div id='mask'></div>").addClass("mask").click(function() {}) .appendTo("body").fadeIn(0); document.getElementById("mask").style.display = "block"; var windowWidth = document.documentElement.clientWidth; var windowHeight = document.documentElement.clientHeight; var popupHeight = $("#previewDiv").height(); var popupWidth = $("#previewDiv").width(); $("#previewDiv").css({ "position": "absolute", "top": (windowHeight-popupHeight)/2+$(document).scrollTop(), "left": (windowWidth-popupWidth)/2 }); $("#previewDiv").show(); } function hide(){ $("#mask").remove(); $("#previewDiv").hide(); } show();</script></body></html>