![ThinkPHP5实战之[教学管理系统]](https://img.php.cn/upload/course/000/000/068/6253d87459486427.png)
批改状态：未批改
老师批语：
收藏
收藏
收藏
会话机制
1. cookie
http协议的无状态问题
服务器对用户访问的跟踪手段
$_COOKIE: 超全局变量数组
setcookie(): 设置客户端cookie
常用操作: 创建/读取/更新/删除
2. session
session_start(): 启动新会话或者重用现有会话
session_id(): 获取/设置当前会话 ID
session_save_path(): 读取/设置当前会话的保存路径
session_encode(): 将当前会话数据编码为一个字符串
session_decode: 解码会话数据
session_destroy(): 销毁一个会话中的全部数据,仅清空而已
session_unset(): 释放所有的会话变量
session_reset(): 回滚到上一次的会话
注意: 必须先执行session_start()开启会话才生效,且之前不能有输出
使用session的好处：能提高安全性，因为本地的cookie只存储服务session的ID，通过ID跟服务器交互获取存储再服务器的session的信息
login.php
<?php
session_start();
//判断是否重复登录
if (isset($_SESSION['user_name'])){
header('location:index.php');
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>用户登录</title>
<style>
h3 {
text-align: center;
}
div {
width: 300px;
height: 150px;
/*background-color: lightblue;*/
margin: 0 auto;
text-align: center;
padding: 20px;
border: 1px dashed #888;
border-radius: 5%;
}
div input {
border: none;
border-bottom: 1px solid #333;
}
button:hover {
cursor: pointer;
background-color: lightblue;
}
.success {
color: green;
}
.error {
color: red;
}
</style>
</head>
<body>
<h3>用户登录</h3>
<div>
<form name="user">
<p>
<label>邮 箱:
<input type="email" name="email" placeholder="name@example.com">
</label>
</p>
<p>
<label>密 码:
<input type="password" name="password" placeholder="******">
</label>
</p>
<p>
<button type="button" onclick="check(this.form)">登录</button>
</p>
<!-- 提示信息占位符-->
<p></p>
</form>
</div>
<script>
// 获取表单
var user = document.forms.namedItem('user');
var tips = user.lastElementChild;
function addEvent(ele,tips,msg) {
ele.addEventListener('blur', function (){
if (this.value.trim().length === 0) {
tips.classList.add('error');
tips.innerHTML = msg;
this.focus();
}
},false);
ele.addEventListener('keydown', function () {
tips.innerText = '';
},false);
}
// 给邮箱和密码元素添加事件
addEvent(user.email, tips, '邮箱不能为空');
addEvent(user.password, tips, '密码不能为空');
// 邮箱与密码需要到数据表中验证,我们通过"Ajax"异步操作实现
function check(form) {
var request = new XMLHttpRequest();
request.onreadystatechange = function () {
if (request.readyState === 4 && request.status === 200) {
// console.log(request.responseText);
var data = JSON.parse(request.responseText);
// 根据返回的状态,添加适当的class样式
if (data.status === 1) {
// 移除之前的样式,确保现有样式有效,如果之前没有样式也不会报错的
tips.classList.remove('error');
// 为成功添加特殊样式,即绿色
tips.classList.add('success');
tips.innerText = data.message;
// 2秒后跳转到上一个页面,即用户列表页
setTimeout(function (){
// 跳转到员工管理后台首页
location.href = 'index.php';
},2000);
}
// 没有更新或更新错误采用同一个样式
else {
tips.classList.add('error');
tips.innerText = data.message;
}
}
};
request.open('POST', 'check.php', true);
request.setRequestHeader('content-type','application/x-www-form-urlencoded');
var data = 'email='+form.email.value.trim()+'&password='+form.password.value.trim();
request.send(data);
}
</script>
</body>
</html>check.php
<?php
session_start();
$status = 0;//默认为0，0为错误
$message = '';
if (empty($_POST['email'])){
$message = '邮箱不能为空';
exit(json_encode(['status'=>$status,'message'=>$message]));
}else{
$email = strtolower(trim($_POST['email']));
}
if (empty($_POST['password'])){
$message = '密码不能为空';
exit(json_encode(['status'=>$status,'message'=>$message]));
}else{
$password = trim($_POST['password']);
}
if ($email && $password){
$pdo = new PDO('mysql:host=127.0.0.1;dbname=php','root','root');
$stmt = $pdo->prepare('SELECT COUNT(*) FROM `user` WHERE `email`=:email AND `password`=:password');
if($stmt->execute(['email'=>$email,'password'=>$password])){
if($stmt->fetchColumn(0)>0 ){
$stmt= $pdo->prepare('SELECT `id`,`name` FROM `user` WHERE `email`=:email AND `password`=:password');
$stmt->execute(['email'=>$email,'password'=>$password]);
$user = $stmt->fetch(PDO::FETCH_ASSOC);
$_SESSION['user_id'] = $user['id'];
$_SESSION['user_name'] = $user['name'];
//修改状态码
$status = 1;
$message = '登录成功..';
exit(json_encode(['status'=>$status,'message'=>$message]));
} else{
$message = '邮箱或密码错误';
exit(json_encode(['status'=>$status, 'message'=>$message]));
}
}else{
die(print_r($stmt->errorInfo()));//项目上线需隐藏报错信息
}
}logout.php
<?php
session_start();
if (isset($_SESSION['user_name'])){
session_destroy();//销毁存放在服务器的一个会话中的全部数据
setcookie('PHPSESSID','',time()-3600,'/');//清空客户端cookie数据
header('location:login.php');//跳转函数header()
}
Copyright 2014-2024 https://www.php.cn/ All Rights Reserved | php.cn | 湘ICP备2023035733号
