js如何设置一个全站都能使用的cookie来记住用户名，记住访客的信息，方便访客下次的操作。js设置一个cookie网上有很多资料，但是只能在同目录下使用，其他地方就失效了。设置全局cookie只需加一个参数即可。
把 document.cookie=c_name+ "=" +escape(value)+
((expiredays==null) ? "" : ";expires="+exdate.toGMTString())
改成 document.cookie=c_name+ "=" +escape(value)+
(expiredays==null) ? "" : ";expires="+exdate.toGMTString())+"; path=/";
下面是完整范例：
<html>
<head>
<script type="text/javascript">
function getCookie(c_name)
{
if (document.cookie.length>0)
{
c_start=document.cookie.indexOf(c_name + "=")
if (c_start!=-1)
{
c_start=c_start + c_name.length+1
c_end=document.cookie.indexOf(";",c_start)
if (c_end==-1) c_end=document.cookie.length
return unescape(document.cookie.substring(c_start,c_end))
}
}
return ""
}
function setCookie(c_name,value,expiredays)
{
var exdate=new Date()
exdate.setDate(exdate.getDate()+expiredays)
document.cookie=c_name+ "=" +escape(value)+
((expiredays==null) ? "" : ";expires="+exdate.toGMTString())
}
function checkCookie()
{
username=getCookie('username')
if (username!=null && username!="")
{alert('Welcome again '+username+'!')}
else
{
username=prompt('Please enter your name:',"")
if (username!=null && username!="")
{
setCookie('username',username,365)
}
}
}
</script>
</head>
<body onLoad="checkCookie()">
</body>
</html>
注意：直接右键用浏览器打开是没有效果的，要放到站点下面才能起效。
再给各位补充一个例子
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>js COOKIE 记住帐号或密码</title>
<script language="javascript" type="text/javascript">
function onLoginLoaded()
{
if(isPostBack == "False")
{
GetLastUser();
}
}
function GetLastUser()
{
var id = "49BAC005-7D5B-4231-8CEA-16939BEACD67";
var usr = GetCookie(id);
if(usr != null)
{
document.getElementById('txtUserName').value = usr;
}
else
{
document.getElementById('txtUserName').value = "001";
}
GetPwdAndChk();
}
//点击登录时触发客户端事件
function SetPwdAndChk()
{
//取用户名
var usr = document.getElementById('txtUserName').value;
alert(usr);
//将最后一个用户信息写入到Cookie
SetLastUser(usr);
//如果记住密码选项被选中
if(document.getElementById('chkRememberPwd').checked == true)
{
//取密码值
var pwd = document.getElementById('txtPassword').value;
alert(pwd);
var expdate = new Date();
expdate.setTime(expdate.getTime() + 14 * (24 * 60 * 60 * 1000));
//将用户名和密码写入到Cookie
SetCookie(usr,pwd, expdate);
}
else
{
//如果没有选中记住密码,则立即过期
ResetCookie();
}
}
function SetLastUser(usr)
{
var id = "49BAC005-7D5B-4231-8CEA-16939BEACD67";
var expdate = new Date();
//当前时间加上两周的时间
expdate.setTime(expdate.getTime() + 14 * (24 * 60 * 60 * 1000));
SetCookie(id, usr, expdate);
}
//用户名失去焦点时调用该方法
function GetPwdAndChk()
{
var usr = document.getElementById('txtUserName').value;
var pwd = GetCookie(usr);
if(pwd != null)
{
document.getElementById('chkRememberPwd').checked = true;
document.getElementById('txtPassword').value = pwd;
}
else
{
document.getElementById('chkRememberPwd').checked = false;
document.getElementById('txtPassword').value = "";
}
}
//取Cookie的值
function GetCookie (name)
{
var arg = name + "=";
var alen = arg.length;
var clen = document.cookie.length;
var i = 0;
while (i < clen)
{
var j = i + alen;
//alert(j);
if (document.cookie.substring(i, j) == arg)
return getCookieVal (j);
i = document.cookie.indexOf(" ", i) + 1;
if (i == 0) break;
}
return null;
}
var isPostBack = "<%= IsPostBack %>";
function getCookieVal (offset)
{
var endstr = document.cookie.indexOf (";", offset);
if (endstr == -1)
endstr = document.cookie.length;
return unescape(document.cookie.substring(offset, endstr));
}
//写入到Cookie
function SetCookie(name, value, expires)
{
var argv = SetCookie.arguments;
//本例中length = 3
var argc = SetCookie.arguments.length;
var expires = (argc > 2) ? argv[2] : null;
var path = (argc > 3) ? argv[3] : null;
var domain = (argc > 4) ? argv[4] : null;
var secure = (argc > 5) ? argv[5] : false;
document.cookie = name + "=" + escape (value) +
((expires == null) ? "" : ("; expires=" + expires.toGMTString())) +
((path == null) ? "" : ("; path=" + path)) +
((domain == null) ? "" : ("; domain=" + domain)) +
((secure == true) ? "; secure" : "");
}
function ResetCookie()
{
var usr = document.getElementById('txtUserName').value;
var expdate = new Date();
SetCookie(usr, null, expdate);
}
</script>
</head>
<body onload="onLoginLoaded()">
<form id="form1">
<div>
用户名:<input type="text" ID="txtUserName" onblur="GetPwdAndChk()">
<input type="password" ID="txtPassword">
密码：<input type="checkbox" ID="chkRememberPwd" />记住密码
<input type="button" OnClick="SetPwdAndChk()" value="进入"/>
</div>
</form>
</body>
</html>