转：JS通过Cookie判断页面是否为首次打开

 1 function Cookie(key,value){
 2     this.key=key;
 3     if(value!=null){
 4         this.value=escape(value);
 5     }
 6     this.expiresTime=null;
 7     this.domain=null;
 8     this.path="/";
 9     this.secure=null;
10 }
11 Cookie.prototype.setValue=function(value){this.value=escape(value);}
12 Cookie.prototype.getValue=function(){return (this.value);}
13 Cookie.prototype.setExpiresTime=function(time){this.expiresTime=time;}
14 Cookie.prototype.getExpiresTime=function(){return this.expiresTime;}
15 Cookie.prototype.setDomain=function(domain){this.domain=domain;}
16 Cookie.prototype.getDomain=function(){return this.domain;}
17 Cookie.prototype.setPath=function(path){this.path=path;}
18 Cookie.prototype.getPath=function(){return this.path;}
19 Cookie.prototype.Write=function(v){
20     if(v!=null){
21         this.setValue(v);
22     }
23     var ck=this.key+"="+this.value;
24     if(this.expiresTime!=null){
25         try{
26             ck+=";expires="+this.expiresTime.toUTCString();;
27         }catch(err){
28             alert("expiresTime参数错误");
29         }
30     }
31     if(this.domain!=null){
32         ck+=";domain="+this.domain;
33     }
34     if(this.path!=null){
35         ck+=";path="+this.path;
36     }
37     if(this.secure!=null){
38         ck+=";secure";
39     }
40     document.cookie=ck;
41 }
42 Cookie.prototype.Read=function(){
43     try{
44         var cks=document.cookie.split("; ");
45         var i=0;
46         for(i=0;i <cks.length;i++){
47             var ck=cks[i];
48             var fields=ck.split("=");
49             if(fields[0]==this.key){
50                 this.value=fields[1];
51                 return (this.value);
52             }
53         }
54         return null;
55     }catch(err){
56         alert("cookie读取错误");
57         return null;
58     }
59 }

 1 <script type="text/javascript" src="Cookie.js"></script>
 2 <script type="text/javascript" language="javascript">
 3 window.onload=function(){
 4     var ck=new Cookie("HasLoaded"); //每个页面的new Cookie名HasLoaded不能相同
 5     if(ck.Read()==null){//未加载过，Cookie内容为空
 6         alert("首次打开页面");
 7         //设置保存时间
 8         var dd = new Date();
 9         dd = new Date(dd.getYear() + 1900, dd.getMonth(), dd.getDate(), dd.getHours(), dd.getMinutes(), dd.getSeconds());
10         dd.setSeconds(dd.getSeconds() + 10);
11         ck.setExpiresTime(dd);
12         ck.Write("true"); //设置Cookie。只要IE不关闭，Cookie就一直存在
13     }else{//Cookie存在，表示页面是被刷新的
14         alert("页面刷新");
15     }
16 }
17 </script>