页面1
HTML代码：
<p id="loginInfo"></p>
JS代码：
(function() {
if (typeof pageVisibility.hidden !== "undefined") {
var eleLoginInfo = document.querySelector("#loginInfo");
var funLoginInfo = function() {
var username = localStorage.username || sessionStorage.username;
if (username) {
eleLoginInfo.innerHTML = '欢迎回来，<strong>' + username + '</strong>';
sessionStorage.username = username;
} else {
eleLoginInfo.innerHTML = '您尚未登录，请<a target="_blank" href="'+ location.href.replace("-1.", "-2.") +'">登录</a>';
}
}
pageVisibility.visibilitychange(function() {
if (!this.hidden) funLoginInfo();
});
funLoginInfo();
// 页面关闭清除localStorage
window.addEventListener("unload", function() {
localStorage.removeItem("username");
})
} else {
alert("弹框？？？没错，因为你的这个浏览器不支持Page Visibility API的啦！");
}
})();
页面2
HTML代码：
<form id="loginForm" action="" method="post">
<p>用户名：<input type="text" name="username" required /></p>
<p>密码：<input type="password" name="password" required /></p>
<p><input type="submit" /></p>
</form>
JS代码：
(function() {
if (typeof window.screenX === "number") {
var eleLoginForm = document.querySelector("#loginForm");
eleLoginForm.addEventListener("submit", function(e) {
localStorage.username = document.querySelector("input[name='username']").value;
alert("登录成功！现在可以回到刚才的页面了！");
this.reset();
e.preventDefault();
}, false);
} else {
alert("弹框？？？没错，因为你的这个浏览器不支持HTML5表单的啦！");
}
})();