下面主要通過代碼給大家展示下javascript記住用戶名和登錄密碼，具體代碼內容請看下文。
第一種方式：
CONTENT
login.html
welcome.html
cookie.js
common.js
login.html
<!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> <meta http-equiv="Content-Type" content="text/html; charset=gb2312" /> <title>login</title> <script type="text/javascript" src="cookie.js"></script> <script type="text/javascript" src="common.js"></script> </head> <body> <form action=""> <p> <span>UserName:</span> <input id="userName" type="text" value=""/></p> <p> <span>Password:</span> <input id="password" type="password" value=""/></p> <p> <span style="font-size:12px; color:blue;">記住密碼</span> <input id="saveCookie" type="checkbox" value="" /></p> <p> <input id="submit" type="button" value="GO" /> </p> </form> </body> </html>
welcome.html
<!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>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>welcome</title>
</head>
<body>
<h1>Welcome!</h1>
<a href="login.html">點擊返回登陸框</a>
</body>
</html>
cookie.js
//新建cookie。
//hours為空字符串時,cookie的生存期至浏覽器會話結束。hours為數字0時,建立的是一個失效的cookie,這個cookie會覆蓋已經建立過的同名、同path的cookie（如果這個cookie存在）。
function setCookie(name,value,hours,path){
var name = escape(name);
var value = escape(value);
var expires = new Date();
expires.setTime(expires.getTime() + hours*3600000);
path = path == "" ? "" : ";path=" + path;
_expires = (typeof hours) == "string" ? "" : ";expires=" + expires.toUTCString();
document.cookie = name + "=" + value + _expires + path;
}
//獲取cookie值
function getCookieValue(name){
var name = escape(name);
//讀cookie屬性，這將返回文檔的所有cookie
var allcookies = document.cookie;
//查找名為name的cookie的開始位置
name += "=";
var pos = allcookies.indexOf(name);
//如果找到了具有該名字的cookie，那麼提取並使用它的值
if (pos != -1){ //如果pos值為-1則說明搜索"version="失敗
var start = pos + name.length; //cookie值開始的位置
var end = allcookies.indexOf(";",start); //從cookie值開始的位置起搜索第一個";"的位置,即cookie值結尾的位置
if (end == -1) end = allcookies.length; //如果end值為-1說明cookie列表裡只有一個cookie
var value = allcookies.substring(start,end); //提取cookie的值
return (value); //對它解碼
}
else return ""; //搜索失敗，返回空字符串
}
//刪除cookie
function deleteCookie(name,path){
var name = escape(name);
var expires = new Date(0);
path = path == "" ? "" : ";path=" + path;
document.cookie = name + "="+ ";expires=" + expires.toUTCString() + path;
}
common.js
function $(objStr){return document.getElementByIdx_x_x(objStr);}
window.onload = function(){
//分析cookie值，顯示上次的登陸信息
var userNameValue = getCookieValue("userName");
$("userName").value = userNameValue;
var passwordValue = getCookieValue("password");
$("password").value = passwordValue;
//寫入點擊事件
$("submit").onclick = function()
{
var userNameValue = $("userName").value;
var passwordValue = $("password").value;
//服務器驗證（模擬）
var isAdmin = userNameValue == "admin" && passwordValue =="123456";
var isUserA = userNameValue == "userA" && passwordValue =="userA";
var isMatched = isAdmin || isUserA;
if(isMatched){
if( $("saveCookie").checked){
setCookie("userName",$("userName").value,24,"/");
setCookie("password",$("password").value,24,"/");
}
alert("登陸成功,歡迎你," + userNameValue + "!");
self.location.replace("welcome.html");
}
else alert("用戶名或密碼錯誤，請重新輸入！");
}
}
第二種方式：
<script type="text/javascript">
window.onload=function onLoginLoaded() {
if(isPostBack == "False") {
GetLastUser();
}
}
function GetLastUser() {
var id = "49BAC005-7D5B-4231-8CEA-16939BEACD67";//GUID標識符
var usr = GetCookie(id);
if (usr != null) {
document.getElementById('txtUserName').value = usr;
}
else {
document.getElementById('txtUserName').value = "001";
}
GetPwdAndChk();
}
//點擊登錄時觸發客戶端事件
function SetPwdAndChk() {
//取用戶名
var usr = document.getElementById('txtUserName').value;
alert(usr);
//將最後一個用戶信息寫入到Cookie
SetLastUser(usr);
//如果記住密碼選項被選中
if(document.getElementById('chkRememberPwd').checked == true) {
//取密碼值
var pwd = document.getElementById('txtPassword').value;
alert(pwd);
var expdate = new Date();
expdate.setTime(expdate.getTime() + 14 * (24 * 60 * 60 * 1000));
//將用戶名和密碼寫入到Cookie
SetCookie(usr, pwd, expdate);
}
else {
//如果沒有選中記住密碼,則立即過期
ResetCookie();
}
}
function SetLastUser(usr) {
var id = "49BAC005-7D5B-4231-8CEA-16939BEACD67";
var expdate = new Date();
//當前時間加上兩周的時間
expdate.setTime(expdate.getTime() + 14 * (24 * 60 * 60 * 1000));
SetCookie(id, usr, expdate);
}
//用戶名失去焦點時調用該方法
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));
}
//寫入到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>
<form id="form1">
<div>
用戶名:<input type="text" ID="txtUserName" onblur="GetPwdAndChk()">
<input type="password" ID="txtPassword">
密碼：
<input type="checkbox" ID="chkRememberPwd" />
記住密碼
<input type="button" OnClick="SetPwdAndChk()" value="進入"/>
</div>
</form>
</body>
以上就是用兩種方式展示javascript記住用戶名和登錄密碼的全部代碼，沒有來得及整理運行效果圖，希望大家能夠喜歡。