案例代码
<!DOCTYPE html> <html lang="en"><head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> </head>
<body> <input type="text" id="username"> <br> <input type="checkbox" name="" id="remember"> 记住用户名
<script> var username = document.querySelector('#username'); var remember = document.querySelector('#remember');
if (localStorage.getItem('username')) { username.value = localStorage.getItem('username'); remember.checked = true; }
remember.addEventListener('change', function() { if (this.checked) { if (username.value == '') { alert('请先填写用户名...'); this.checked = false; return false; } localStorage.setItem('username', username.value); } else { localStorage.removeItem('username'); } }) </script> </body>
</html>