下面一個(gè)案例使用js實(shí)現(xiàn)一個(gè)頁面浮層效果，并且通過兩種方法使用js讀寫cookie來實(shí)現(xiàn)用戶關(guān)閉廣告的顯示狀態(tài)；

讀者可以將下面代碼復(fù)制到一個(gè)html文件試試效果；html的pre標(biāo)簽未兩種js實(shí)現(xiàn)的方式

復(fù)制代碼代碼如下:

 
<!DOCTYPE HTML> 
<html> 
<head> 
<meta content="text/html;charset=utf-8" http-equiv="Content-Type"/> 
<meta content="楊凱" name="description"/> 
<meta name="author" content="http://blog.csdn.net/tianyazaiheruan"/> 
<meta name="copyright" content="楊凱版權(quán)所有"/> 
<title>IT_Blog_楊凱</title> 
</head> 
<body> 
<div> 
本文作者：IT_Blog_楊凱 
轉(zhuǎn)載請(qǐng)指明出處：<a href=”http://blog.csdn.net/yangkai_hudong”>http://blog.csdn.net/yangkai_hudong</a> 
</div> 
<br> 
<div> 
<pre> 
1.第一種：使用jQuery的cookie庫 
例子就是現(xiàn)在正在使用的js,相關(guān)代碼如下： 
$(document).ready(function () { 
var adCookie=$.cookie("docCookie"); 
//如果本地沒有cookie，將詞條cookie寫入本地 
if(adCookie!="adDocCookie"){ 
$("#wapDocCookie").show(); 
} 
//如果本地存在詞條cookie，不顯示浮層 
if(adCookie=="adDocCookie"){ 
$("#wapDocCookie").hide(); 
} 
//關(guān)閉廣告，隱藏浮層 
$("#closeAd").click(function(){ 
$("#wapDocCookie").hide(); 
$.cookie("docCookie","adDocCookie",{expires:60}); 
}); 

}); 
//jQuery cookie library 
jQuery.cookie = function(name, value, options) { 
if (typeof value != 'undefined') { // name and value given, set cookie 
options = options || {}; 
if (value === null) { 
value = ''; 
options.expires = -1; 
} 
var expires = ''; 
if (options.expires && (typeof options.expires == 'number' || options.expires.toUTCString)) { 
var date; 
if (typeof options.expires == 'number') { 
date = new Date(); 
date.setTime(date.getTime() + (options.expires * 24 * 60 * 60 * 1000)); 
} else { 
date = options.expires; 
} 
expires = '; expires=' + date.toUTCString(); // use expires attribute, max-age is not supported by IE 
} 
var path = options.path ? '; path=' + (options.path) : ''; 
var domain = options.domain ? '; domain=' + (options.domain) : ''; 
var secure = options.secure ? '; secure' : ''; 
document.cookie = [name, '=', encodeURIComponent(value), expires, path, domain, secure].join(''); 
} else { // only name given, get cookie 
var cookieValue = null; 
if (document.cookie && document.cookie != '') { 
var cookies = document.cookie.split(';'); 
for (var i = 0; i < cookies.length; i++) { 
var cookie = jQuery.trim(cookies[i]); 
// Does this cookie string begin with the name we want? 
if (cookie.substring(0, name.length + 1) == (name + '=')) { 
cookieValue = decodeURIComponent(cookie.substring(name.length + 1)); 
break; 
} 
} 
} 
return cookieValue; 
} 
}; 
2.第二種：自己寫一個(gè)js操作cookie的實(shí)例 
相關(guān)js如下： 
$(document).ready(function() { 

function writeCookie(name,value) 
{ 
var exp = new Date(); 
exp.setTime(exp.getTime() + 7*24*60*60*1000); 
document.cookie = name + "="+ escape (value) + ";expires=" + exp.toGMTString(); 
} 
//讀取cookies 
function readCookie(name) 
{ 
var arr,reg=new RegExp("(^| )"+name+"=([^;]*)(;|$)"); 
if(arr=document.cookie.match(reg)){ 
return unescape(arr[2]); 
}else { 
return null; 
} 
} 
var adCookie = readCookie("adCookie"); 

if(adCookie!="adDocCookie"){ 
$("#wapDocCookie").show(); 
} 
//如果本地存在詞條cookie，不顯示浮層 
if(adCookie=="adDocCookie"){ 
$("#wapDocCookie").hide(); 
} 

//關(guān)閉廣告，隱藏浮層 
$("#closeAd").click(function(){ 
$("#wapDocCookie").hide(); 
}); 
}); 
</pre> 
</div> 
<!--廣告樣式 --> 
<style type="text/css"> 
body {TEXT-ALIGN: center;} 
#wapDocCookie{background-color:rgba(0,0,0,0.7);background:#4b4b4b\9;width:100%;text-align:center;position:fixed;padding:10px 0 5px 0;bottom:0;left:0;} 
#bkguancha{background:url(http://static.hudong.com/35/86/26100000006141138683868789461.png) no-repeat;background-size:280px;background:url(http://static.hudong.com/50/69/26100000006141138683695381873.png) no-repeat 0 -36px\9;height:46px;width:290px;display:inline-block;overflow:hidden;line-height:99em;} 
#closeAd{background:url(http://static.hudong.com/54/88/26100000006141138683883031718.png) no-repeat ;background-size:12px;background:url(http://static.hudong.com/50/69/26100000006141138683695381873.png) no-repeat -278px 0\9;height:12px;width:12px;display:block;position:absolute;top:5px;right:10px;} 
<!--廣告js --> 
</style> 
<script type="text/javascript" src="http://www.huimg.cn/lib/jquery-1.3.2.js"></script> 
<script type="text/javascript"> 
$(document).ready(function () { 
var adCookie=$.cookie("docCookie"); 
//如果本地沒有cookie，將詞條cookie寫入本地 
if(adCookie!="adDocCookie"){ 
$("#wapDocCookie").show(); 
} 
//如果本地存在詞條cookie，不顯示浮層 
if(adCookie=="adDocCookie"){ 
$("#wapDocCookie").hide(); 
} 
//關(guān)閉廣告，隱藏浮層 
$("#closeAd").click(function(){ 
$("#wapDocCookie").hide(); 
$.cookie("docCookie","adDocCookie",{expires:60}); 
}); 

}); 
//jQuery cookie library 
jQuery.cookie = function(name, value, options) { 
if (typeof value != 'undefined') { // name and value given, set cookie 
options = options || {}; 
if (value === null) { 
value = ''; 
options.expires = -1; 
} 
var expires = ''; 
if (options.expires && (typeof options.expires == 'number' || options.expires.toUTCString)) { 
var date; 
if (typeof options.expires == 'number') { 
date = new Date(); 
date.setTime(date.getTime() + (options.expires * 24 * 60 * 60 * 1000)); 
} else { 
date = options.expires; 
} 
expires = '; expires=' + date.toUTCString(); // use expires attribute, max-age is not supported by IE 
} 
var path = options.path ? '; path=' + (options.path) : ''; 
var domain = options.domain ? '; domain=' + (options.domain) : ''; 
var secure = options.secure ? '; secure' : ''; 
document.cookie = [name, '=', encodeURIComponent(value), expires, path, domain, secure].join(''); 
} else { // only name given, get cookie 
var cookieValue = null; 
if (document.cookie && document.cookie != '') { 
var cookies = document.cookie.split(';'); 
for (var i = 0; i < cookies.length; i++) { 
var cookie = jQuery.trim(cookies[i]); 
// Does this cookie string begin with the name we want? 
if (cookie.substring(0, name.length + 1) == (name + '=')) { 
cookieValue = decodeURIComponent(cookie.substring(name.length + 1)); 
break; 
} 
} 
} 
return cookieValue; 
} 
}; 
</script> 

<div id="wapDocCookie" style="display: none;"> 
<a id="bkguancha"  onclick="StatVirtualTraffic(document.referrer,window.location,'stat_hdstat_onclick_survey_wap_doc_foot_download')">點(diǎn)擊下載</a> 
<a title="關(guān)閉" id="closeAd" href="javascript:void(0)"> </a> 
</div> 
</body> 
</html> 