很多登录功能上都有个“记住密码”的功能，其实无非就是对cookie的读取。
下面展示这个功能的代码，原作者已无法考究。。。。
测试方法：直接输入账号密码，提交后，刷新页面，再输入同样的账号，就可以显示
<!DOCTYPE HTML> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>js COOKIE 记住帐号或密码</title> <script type="text/javascript"> window.onload=function onLoginLoaded() { if (isPostBack == "False") { GetLastUser(); } } function GetLastUser() { var id = "49BAC005-7D5B-4231-8CEA-16939BEACD67";//GUID标识符 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)) + ((domain == null) "; domain=" + domain)) + ((secure == true) "); } function ResetCookie() { var usr = document.getElementById('txtUserName').value; var expdate = new Date(); SetCookie(usr, null, expdate); } </script> </head> <body> <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" value="进入"/> </div> </form> </body> </html>
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