sessiond的用法

一、connect.inc.php

<?php
    define("DSN","mysql:host=localhost;dbname=test");
    define("DBUSER","root");
    define("DBPWD","playboy");
    
    try{
        $pdo=new PDO(DSN,DBUSER,DBPWD);
    }catch(PDOException $e){
        die("链接失败：'.$e->getMessage());
    }

二、login.php

<?php
    $session_start();
    require "connect.inc.php";
    if(isset($_POST['sub'])){
        $stmt=$pdo->prepare("select id,username from user where username=? and password=?");
        $stmt->execute(array($_POST["username"]),md5($_POST["password"]));
        if($stmt->rowcount()>0){
            $_SESSION=$stmt->fetch(PDO::FETCH_ASSOC);
            $_SESSION["isLogin"]=1;
            header("Location:index.php");
        }else{
            echo '<font color="red">用户名或密码错误！</font>';
        }
    }
   ?>
   //...注册表单

三、index.php

<?php
    session_start();
    if(isset($_SESSION['isLogin'])&&$_SESSION['isLogin']===1){
        echo "<p>当前用户为：<b>".$_SESSION["username"]."</b>,&nbsp;";
        echo "<a href='loginout.php'>退出</a></p>";
    }else{
        header("Location:login.php");
        exit;
    }
    //...主页html信息

四、logout.php

<?php
    session_strart();
    $username=$_SESSION["username"];
    $_SESSION=array();
    if(issset($_COOKIE[session_name()])){
        setcookie(session_name(),'',time()-4200,'/');
    }
    session_destory();
    //...html信息