利用会话控制实现页面登录与注销功能

来源：枰培教育

首先是一个普通的登陆页面实现

登录页面login.php

<!DOCTYPE html>
<html>
 <head>
 <title>登陆页</title>
 <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" integrity="sha384-MCw98/SFnGE8fJT3GXwEOngsV7Zt27NXFoaoApmYm81iuXoPkFOJwJ8ERdknLPMO" crossorigin="anonymous">
 </head>
 <body>
 <div>
 <div class="card col-12 mt-5">
 <div>
 <h4>
 用户登录
 </h4>
 <div class="col-12 mt-4 d-flex justify-content-center">
 <form method="post" action="action.php">
 <input type="hidden" name="action" value="login">
 <div>
 <label for="username">用户名</label>
 <input type="text"
 class="form-control"
 id="username"
 name="username"
 placeholder="请输入用户名">
 </div>
 <div>
 <label for="password">密码</label>
 <input type="password"
 class="form-control"
 id="password"
 name="password"
 placeholder="请输入密码">
 </div>
 <div class="form-group form-check">
 <input type="checkbox"
 class="form-check-input"
 id="remember"
 name="remember">
 <label
 for="remember">
 在这台电脑上记住我的登录状态
 </label>
 </div>
 <button type="submit"
 class="btn btn-primary">
 登录
 </button>
 </form>
 </div>
 </div>
 </div>
 </div>
 </body>
</html>

登录功能实现action.php

 <?php
 session_start();
 switch ($_REQUEST['action']) {
 case 'login':
 $username = $_POST['username'];
 $password = $_POST['password'];
 $remember = $_POST['remember'];
 $user = getUser();
 if ($username != $user['username']) {
 // 登录失败
 sendLoginFailedResponse();
 }
 if ($password != $user['password']) {
 // 登录失败
 sendLoginFailedResponse();
 }
 if ($remember) {
 rememberLogin($username);
 }
 $_SESSION['username'] = $username;
 header("location:index.php");
 break;
 case 'logout':
 session_unset();
 setcookie("username", "", time() - 1);
 header("location:login.php");
 break;
 }
 function getUser() {
 return array(
 "username" => "cyy",
 "password" => "123456"
 );
 }
 function sendLoginFailedResponse() {
 $response = "<script>
 alert('用户名或密码错误！');
 window.location='login.php';
 </script>";
 echo $response;
 die;
 }
 function rememberLogin($username) {
 setcookie("username", $username, time() + 7 * 24 * 3600);
 }

首页index.php

<?php
 session_start();
 if (rememberedLogin()) {
 $_SESSION['username'] = $_COOKIE['username'];
 }
 if (!hasLoggedIn()) {
 header("location:login.php");
 die;
 }
 function hasLoggedIn() {
 return isset($_SESSION['username']) && validateUsername($_SESSION['username']);
 }
 function validateUsername($username) {
 return $username == "cyy";
 }
 function rememberedLogin() {
 return isset($_COOKIE['username']) && validateUsername($_COOKIE['username']);
 }
 ?>
 <!DOCTYPE html>
 <html>
 <head>
 <title>主页</title>
 <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" integrity="sha384-MCw98/SFnGE8fJT3GXwEOngsV7Zt27NXFoaoApmYm81iuXoPkFOJwJ8ERdknLPMO" crossorigin="anonymous">
 </head>
 <body>
 <div>
 <nav class="navbar navbar-light bg-light">
 <a>
 使用 Cookie 和 Session 实现会话控制
 </a>
 <a href="action.php?action=logout">
 <button class="btn btn-outline-danger my-2 my-sm-0"
 type="button">
 注销
 </button>
 </a>
 </nav>
 <div class="d-flex justify-content-around mt-5">
 <div class="card col-5">
 <div>
 <h5>
 会话控制实战内容一
 </h5>
 <h6 class="card-subtitle mb-2 text-muted">
 SESSION 部分
 </h6>
 <p>
 实现用户认证功能，用户登录、退出与身份识别
 </p>
 </div>
 </div>
 <div class="card col-5">
 <div>
 <h5>
 会话控制实战内容二
 </h5>
 <h6 class="card-subtitle mb-2 text-muted">
 COOKIE 部分
 </h6>
 <p>
 实现登录记住用户功能，七天免登录认证
 </p>
 </div>
 </div>
 </div>
 <div class="d-flex justify-content-around mt-4">
 <div class="card col-5">
 <div>
 <h5>
 会话控制实战内容一
 </h5>
 <h6 class="card-subtitle mb-2 text-muted">
 SESSION 部分
 </h6>
 <p>
 实现用户认证功能，用户登录、退出与身份识别
 </p>
 </div>
 </div>
 <div class="card col-5">
 <div>
 <h5>
 会话控制实战内容二
 </h5>
 <h6 class="card-subtitle mb-2 text-muted">
 COOKIE 部分
 </h6>
 <p>
 实现登录记住用户功能，七天免登录认证
 </p>
 </div>
 </div>
 </div>
 </div>
 </body>
 </html>

接下来是会话控制实例：许愿墙源码

许愿墙首页index.php

 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
 <head>
 <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
 <title>许愿墙</title>
 <link rel="stylesheet" href="Css/index.css" />
 <script type="text/javascript" src='Js/jquery-1.7.2.min.js'></script>
 <script type="text/javascript" src='Js/index.js'></script>
 </head>
 <body>
 <div id='top'>
 <a href="wish.php"><span id='send'></span></a>
 </div>
 <div id='main'>
 <?php
 //连接数据库
 $connection=mysqli_connect('127.0.0.1','root','123456');
 if(mysqli_connect_error()){
 die(mysqli_connect_error());
 }
 mysqli_select_db($connection,'wall');
 mysqli_set_charset($connection,'utf8');
 $sql="SELECT * FROM wall";
 $result=mysqli_query($connection,$sql);
 //显示留言
 while($row=mysqli_fetch_assoc($result)){
 $wish_time=$row['wish_time'];
 $time=date('Y-m-d H:i:s',$wish_time);
 $id=$row['id'];
 //判断留言板颜色
 switch($row['color']){
 case 'a1':
 echo "<dl class='paper a1'>";
 break;
 case 'a2':
 echo "<dl class='paper a2'>";
 break;
 case 'a3':
 echo "<dl class='paper a3'>";
 break;
 case 'a4':
 echo "<dl class='paper a4'>";
 break;
 case 'a5':
 echo "<dl class='paper a5'>";
 break;
 default:
 echo "<dl class='paper a1'>";
 break;
 }
 echo "<dt>";
 echo "<span>{$row['name']}</span>";
 echo "<span>No.{$row['id']}</span>";
 echo "</dt>";
 echo "<dd>{$row['content']}</dd>";
 echo "<dd>";
 echo "<span>{$time}</span>";
 echo "<a href="delete.php?num={$id}"></a>";
 echo "</dd>";
 echo "</dl>";
 }
 mysqli_close($connection);
 ?>
 </div>
 
 <!--[if IE 6]>
 <script type="text/javascript" src="./Js/iepng.js"></script>
 <script type="text/javascript">
 DD_belatedPNG.fix('#send,#close,.close','background');
 </script>
 <![endif]-->
 </body>
 </html>

添加愿望页面wish.php

<!DOCTYPE >
 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
 <head>
 <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
 <title>许愿墙</title>
 <link rel="stylesheet" href="Css/index.css" />
 <script type="text/javascript" src='Js/jquery-1.7.2.min.js'></script>
 <script type="text/javascript" src='Js/index.js'></script>
 <style type="text/css">
 #content {
 width: 638px;
 height:650px;
 margin:0 auto;
 margin-top:100px;
 /*background-color:#F0FAFF;
 border:2px solid #C9F;*/
 }
 #content .c-top{
 width: 638px;
 height: 80px;
 background: url(./Images/content_top.jpg) no-repeat;
 }
 #content .c-bottom{
 width: 638px;
 height: 50px;
 background: url(./Images/content_bottom.jpg) no-repeat;
 }
 .c-content{
 width: 638px;
 height: 470px;
 background: url(./Images/content_bg.jpg) repeat;
 }
 .papercolor{
 width:588px;
 height: 60px;
 margin-left: 35px;
 padding-top:15px;
 }
 .p-left{
 float: left;
 width: 120px;
 line-height: 27px;
 }p-left
 .p-right{
 float: left; 
 }
 .color330{
 float: left;
 margin-left: 20px;
 border-right: #404040 1px solid; 
 border-top: #404040 1px solid; 
 border-left:#404040 1px solid;
 width: 25px;
 cursor: pointer;
 border-bottom: #404040 1px solid;
 height: 25px;
 }
 .papercontent{
 width: 588px;
 height: 210px;
 margin-left: 35px;
 }
 .left{
 width: 294px;
 height:100px;
 float: left;
 }
 .right{
 width: 294px;
 height:100px;
 float: left;
 }
 .left-top{
 margin-bottom: 10px;
 }
 .left-bottom{
 }
 .right-top{
 margin-bottom: 10px;
 }
 .right-bottom{
 width:200px;
 height:150px;
 border: 1px solid orange;
 margin-left:20px;
 background-color:#E8DEFF;
 }
 .name{
 clear: both;
 width: 588px;
 height: 50px;
 margin-left: 35px;
 margin-top:10px;
 }
 .name-left{
 width:60px;
 height: 26px;
 line-height: 26px;
 float: left;
 }
 .name-right{
 float: left;
 }
 .name-right input{
 width: 200px;
 height: 26px;
 }
 .code{
 clear: both;
 width: 588px;
 height: 50px;
 margin-left: 35px;
 margin-top:10px;
 }
 .code-left{
 width:50px;
 height: 26px;
 line-height: 26px;
 float: left;
 }
 .code-content{
 width:100px;
 float: left;
 }
 .code-content input{
 width: 100px;
 height: 26px;
 }
 .code-right{
 float:left;
 margin-left: 10px;
 }
 .code-right input{
 width: 40px;
 height: 26px;
 background-color: pink;
 }
 .submit{
 width:174px;
 height:38px;
 background: url(./Images/pic_submit.gif) no-repeat;
 margin-left:217px;
 }
 .shuname{
 width:80px;
 height:25px;
 margin-left: 120px;
 }
 span{
 font-size: 13px;
 font-family: "微软雅黑";
 }
 </style>
 
 </head>
 <body>
 <div id='top'></div>
 <div id="content">
 <div></div>
 <form action="add.php" method="post" id="myfrom">
 <div>
 <div>
 <div>
 <span>请选择纸条颜色:</span>
 </div>
 <div>
 <div id="a1" style="background:#FFDFFF"></div>
 <div id="a2" style="background:#C3FEC0"></div>
 <div id="a3" style="background:#FFE3b8"></div>
 <div id="a4" style="background:#CEECFF"></div>
 <div id="a5" style="background:#E8DEFF"></div>
 <input type="hidden" value="" name="idvalue" id="idvalue"> 
 </div>
 </div>
 <div>
 <div>
 <div>
 <span>输入你的祝福纸条内容:</span>
 </div>
 <div>
 <textarea cols="25" rows="8" id="textfont" name="textfont"></textarea>
 </div>
 </div>
 <div>
 <div>
 <span>纸条效果预览:</span>
 </div>
 <div>
 <div style="height:15px"><span>第x条</span><br/></div>
 <div style="height:100px;margin-top:10px"><span id="font"></span></div>
 <div><span id="name">署名:</span></div> 
 </div>
 </div>
 </div>
 <div>
 <div>
 <span>您的署名:</span>
 </div>
 <div>
 <input id="nameright" type="text" name="name" value="">
 </div>
 </div>
 <div>
 <div>
 <span>验证码:</span>
 </div>
 <div>
 <input id="codeone" type="text" name="recode" value=""><span></span>
 </div>
 <div>
 <input id="codetwo" type="text" name="code" value="<?php echo mt_rand(1000,9999); ?>" readonly>
 </div> 
 </div>
 <!--<div><button type="submit" style="width:174px;height:38px"></button></div>-->
 <input style="BORDER-RIGHT: #f33b78 1px outset; BORDER-TOP: #f33b78 1px outset; FONT-WEIGHT: bold; BORDER-LEFT: #f33b78 1px outset; COLOR: #ffffff; BORDER-BOTTOM: #f33b78 1px outset; BACKGROUND-COLOR: #70ae0b;margin-left: 225px" type="submit" value="→ 开始贴许愿小纸条 ←" name="submit" id="submit">
 
 <a href="index.php"><input type="button" name="Submit2" value="返回"></a> 
 </div>
 </form>
 <hr/ style="color:orange;width:550">
 <div></div>
 </div>
 <!--[if IE 6]>
 <script type="text/javascript" src="./Js/iepng.js"></script>
 <script type="text/javascript">
 DD_belatedPNG.fix('#send,#close,.close','background');
 </script>
 <![endif]-->
 <script type="text/javascript">
 //改变颜色
 $(".color330").click(function(){ 
 var value=$(this).css("background-color");
 var idvalue=$(this).attr("id");
 console.log(idvalue);
 $("#idvalue").attr("value",idvalue);
 $(".right-bottom").css("background-color",value);
 })
 //改变值触发的事件
 var textfont = document.getElementById('textfont');
 var font = document.getElementById('font');
 textfont.onchange=function(){
 font.innerHTML=textfont.value; 
 }
 //改变值触发的事件
 var nameright = document.getElementById('nameright');
 nameright.onchange=function(){
 document.getElementById("name").innerText="署名: "+nameright.value; 
 }
 
 //在填写完毕验证码之后验证是否一致
 var codeone = document.getElementById('codeone');
 var codetwo = document.getElementById('codetwo');
 //表单时区焦点事件
 codeone.onblur=function(){
 //验证两次验证码是否一致
 if(codeone.value != codetwo.value){
 this.nextSibling.innerHTML='验证码不一致!'
 this.nextSibling.style.color='red';
 }
 }
 $( '#submit' ).click( function () {
 window.location.href="add.php"; 
 } );
 
 </script>
 </body>
 </html>

新增愿望实现add.php

 <?php
 // 获取表单提交数据
 $name=$_POST['name'];
 $textfont=$_POST['textfont'];
 $wish_time=time();
 $color=$_POST['idvalue'];
 // 数据库操作
 $connection=mysqli_connect('127.0.0.1','root','123456');
 if(mysqli_connect_error()){
 die(mysqli_connect_error());
 }
 mysqli_select_db($connection,'wall');
 mysqli_set_charset($connection,'utf8');
 $sql="INSERT INTO wall(content,name,wish_time,color) VALUES('$textfont','$name',$wish_time,'$color')";
 $result=mysqli_query($connection,$sql);
 if($result){
 echo '<script>alert("发布成功！");document.location = "index.php";</script>';
 }else{
 echo '<script>alert("发布失败！");document.location = "index.php";</script>';
 }
 mysqli_close($connection);
 ?>

删除愿望delete.php

 <?php
 //接受要删除的留言id
 $num=$_GET['num'];
 // 数据库操作
 $connection=mysqli_connect('127.0.0.1','root','123456');
 if(mysqli_connect_error()){
 die(mysqli_connect_error());
 }
 mysqli_select_db($connection,'wall');
 mysqli_set_charset($connection,'utf8');
 $sql="DELETE FROM wall WHERE id=$num";
 $result=mysqli_query($connection,$sql);
 if($result){
 echo '<script>alert("删除成功！");document.location = "index.php";</script>';
 }else{
 echo '<script>alert("删除失败！");document.location = "index.php";</script>';
 }
 mysqli_close($connection);
 ?>

附上数据库结构wall.sql

-- phpMyAdmin SQL Dump
-- version 4.8.5
-- https://www.phpmyadmin.net/
--
-- 主机： localhost
-- 生成日期： 2019-08-18 22:08:38
-- 服务器版本： 8.0.12
-- PHP 版本： 7.3.4
SET SQL_MODE = "NO_AUTO_VALUE_ON_ZERO";
SET AUTOCOMMIT = 0;
START TRANSACTION;
SET time_zone = "+00:00";
/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8mb4 */;
--
-- 数据库： `wall`
--
-- --------------------------------------------------------
--
-- 表的结构 `wall`
--
CREATE TABLE `wall` (
 `id` tinyint(4) NOT NULL COMMENT '留言编号',
 `content` varchar(200) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '留言内容',
 `name` varchar(20) NOT NULL DEFAULT '匿名的宝宝' COMMENT '署名',
 `wish_time` int(11) NOT NULL COMMENT '留言时间',
 `color` char(2) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '留言背景色'
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
--
-- 转存表中的数据 `wall`
--
INSERT INTO `wall` (`id`, `content`, `name`, `wish_time`, `color`) VALUES
(17, '111', '111', 1566136880, 'a1'),
(19, '333', '333', 156613, 'a3'),
(21, '555', '555', 1566136911, 'a5'),
(24, '9999', '9999', 1566137235, 'a4');
--
-- 转储表的索引
--
--
-- 表的索引 `wall`
--
ALTER TABLE `wall`
 ADD PRIMARY KEY (`id`);
--
-- 在导出的表使用AUTO_INCREMENT
--
--
-- 使用表AUTO_INCREMENT `wall`
--
ALTER TABLE `wall`
 MODIFY `id` tinyint(4) NOT NULL AUTO_INCREMENT COMMENT '留言编号', AUTO_INCREMENT=26;
COMMIT;
/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;

知识点补充：

【使用 COOKIE 实现会话控制】

用于存储用户关键信息

保存在客户端（浏览器）

通过 HTTP 请求/响应头传输

【COOKIE 失效】

● COOKIE过期

● 用户手动删除 COOKIE

● 服务器清除 COOKIE 的有效性

【使用 SESSION 实现会话控制】

● 用于存储用户相关信息

● 保存在服务端

● 通过保存在客户端的 SESSION ID 来定位 SESSION 内容

【SESSION 失效/清除】

● COOKIE过期（关闭浏览器）

● 用户手动删除 COOKIE

● 服务端删除 SESSION 文件或清空 SESSION 内容

更多相关php知识，请访问php教程！