php - 使用 cookie 时注销

Question

我是使用 php cookie 的初学者，我正在尝试使用 cookie 制作一个简单的登录和注销表单。一切都很好，但是当我按注销链接时，我无法注销。要注销，我必须从浏览器中删除 cookie。

登录页面

<?php
session_start();

if (isset($_COOKIE["Email"])){
    header("location: home.php");    
}
?>


<form method="post" action="log_in.php">   
<font size="6">Sign In</font>

Email Address: </b></font><input type="text" name="Email" id="email"  />  

password:  <input type="password" name="password" id="password"  />    

<input type="checkbox" name="rememberMe" value="1" id="check"/> Remember Me

<input type="submit" name="Login" id="sign" value="sign in" >

<?php 
include 'db.php';
if(isset($_POST['Login'])){
    $user_email = $_POST['Email'];  
    $password = $_POST['password'];

    $check_user = "SELECT * FROM user where user_email  = '$user_email' AND user_pass = '$password'";
    $run = mysql_query($check_user );

    if (mysql_num_rows($run) > 0){
        $_SESSION['Email']= $user_email;   

        $_SESSION['start'] = time(); 
        if(isset($_POST['rememberMe'])){
            $expire=time()+120;
            setcookie("Email", "Email", $expire);
        }
    else{
        $expire=time()+30;
        setcookie("Email", "Email", $expire);
    }
    echo "<script>window.open('home.php','_self')</script>";   
}
else {
    echo "<script>alert('email or password incorrect!')</script>";     
}}
?>

首页

<?php
if (isset($_COOKIE["Email"])){
  echo "Welcome " . $_COOKIE["Email"] . "!<br>";
    echo '<a href="logoutForm.php">logout</a>';
}
else{
    $now = time(); // Checking the time now when home page starts.
    if ($now > $expire) {
        session_destroy();
        header("location: log_in.php");    
}}

退出页面

 <?php
 session_start();
 unset($_SESSION['Email']);
 session_destroy();
 header("Location: log_in.php");

 if(isset($_SESSION['Email'])):
     setcookie($_SESSION['Email'],'',time()-7000000,'/');
 endif;
 ?>

Answer 1

您的主页(代码)没有 session_start(); 至少在您发布的内容中没有；使用session_destroy()时需要它;它本身不起作用。

尝试一下:

旁注: $expire 对于 home page 代码未定义，因此您需要使用相同的或与您在其他页面使用的类似方法。

<?php
if (isset($_COOKIE["Email"])){
  echo "Welcome " . $_COOKIE["Email"] . "!<br>";
    echo '<a href="logoutForm.php">logout</a>';
}
else{
    $now = time(); // Checking the time now when home page starts.
    if ($now > $expire) { // $expire is undefined
        session_start(); // <= required
        session_destroy(); // <= does not work on its own
        header("location: log_in.php");    
    }
}