一、什么是会话
// cookie：再客户端(浏览器)保存用户信息// 第一次访问一个php脚本文件// 那么这个php可以通过一个函数来给客户端设置cookie// 服务器识别用户，是通过用户使用的终端/浏览器来识别// 开启一个会话// session_start();/** * 执行两个动作 * 1、浏览器：PHPSESSID，基于cookie * 2、服务器：创建一个与PHPSESSID同名的会话文件 */// $_SESSION['email'] = 'admin@php.cn';// $_SESSION['password'] = md5(md5('123456').'php.cn888');// $_SESSION = [];// 直接将服务器上的会话文件删除// session_destroy();
二、会话实例
<!DOCTYPE html><html lang="en"><?phpsession_start(); //开启一个会话// 判断用户是否已经登录if(isset($_SESSION['user'])){ // unserialize()函数需要处理序列化之后的字符串,然后将其反序列化为php的值 $user = unserialize($_SESSION['user']);}?><head> <meta charset="UTF-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>session</title></head><body> <nav> <?php if(isset($user)) : ?> <a href="" id="logout">退出</a> <?php else : ?> <a href="login.php">登录</a> <?php endif ?> </nav> <script> document.querySelector('#logout').addEventListener('click', function(event) { if (confirm('是否退出?')) { // 禁用默认跳转行为 event.preventDefault(); // 跳转到处理器 location.assign('handle.php?action=logout'); } }); </script></body></html>
<!DOCTYPE html><html lang="en"><?php session_start();// 判断用户是否已经登录if(isset($_SESSION['user'])){ echo '<script>alert("不要重复登录");location.href="index.php"</script>';}?><head> <meta charset="UTF-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>登录</title></head><body> <form action="handle.php?action=login" method="post"> <fieldset> <legend>用户登录</legend> <p> <input type="email" name="email" placeholder="user@email.com" require> </p> <p> <input type="password" name="password" placeholder="不少于6位" require> </p> <p> <button>提交</button> </p> </fieldset> <a href="register.php">如果没有账号，请先注册</a> </form></body></html>
<!DOCTYPE html><html lang="en"><?phpsession_start();// 判断用户是否已经登录if(isset($_SESSION['user'])){ echo '<script>alert("不要重复登录");location.href="index.php"</script>';}?><head> <meta charset="UTF-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=], initial-scale=1.0"> <title>注册</title></head><body> <form action="handle.php?action=register" method="post"> <fieldset> <legend>用户注册</legend> <p> <input type="text" name="name" placeholder="请输入" require> </p> <p> <input type="email" name="email" placeholder="user@email.com" require> </p> <p> <input type="password" name="password" placeholder="不少于6位" require> </p> <p> <button>提交</button> </p> </fieldset> </form></body></html>
