Question

我已尝试过所有内容，但没有任何作用，因此，我创建了一个登录页面。现在当我首先登录时出现错误：

注意：未定义的索引：在第39行的C：\ wamp \ www \ ucp \ index.php中登录

然后当我登录时，它首先不会改变页面外观：

这是整个代码

<?php 

$con = mysqli_connect("localhost","root","","samp");

if (mysqli_connect_errno())
{
    echo "Failed to connect to the database: " . mysqli_connect_error();
    die();
}

session_start();

if(isset($_GET['logout']))
{
    setcookie("login", '',time()-86400); # delete cookie
    exit(); # stop executing here
    header('index.php');
}


if(!empty($_POST['username']) && !empty($_POST['password']))
{

    $userName = isset($_POST["username"]) ? $_POST["username"] : null;
    $userPass = isset($_POST["password"]) ? $_POST["password"] : null;

    $hashedPass = hash('whirlpool', $userPass);
    $query = "SELECT Ime FROM Igraci WHERE Ime = '$userName' AND Lozinka = '$hashedPass'";

    $result = mysqli_query( $con, $query);

    $row = mysqli_fetch_array($result);

    if($row)
    {
        $session = md5($userName.$hashedPass);
        mysqli_query($con, "UPDATE Igraci SET session = '$session' WHERE Ime = '$userName' AND Lozinka = '$hashedPass'");
        setcookie("login", $session,time()+3600);
        echo "You are now logged in with hash: ".htmlspecialchars($_COOKIE["login"]). '<a href="index.php?logout=1">logout</a>?';

    }
    else
    {
        die('Account has not been found.');
    }
}

if(isset($_COOKIE["login"]) && mb_strlen(isset($_COOKIE["login"]) == '32'))
{
    $session = $con->real_escape_string($_COOKIE["login"]);
    $query = "SELECT Ime FROM Igraci WHERE session = '$session' LIMIT 1";
    $result = mysqli_query( $con, $query); $row = mysqli_fetch_array($result);

    if($row['Ime']) 
    { 
        echo "User is already logged in with username ".$row['Ime']. " and hash: ".htmlspecialchars($_COOKIE["login"]). '<a href="index.php?logout=1">logout</a>?';
        exit(); 
    }

}

?>

<!DOCTYPE html>
<html>
<head>
    <title>Roleplay Factory User Control Panel</title>
    <link rel="stylesheet" type="text/css" href="style.css">
    <link href='https://fonts.googleapis.com/css?family=Roboto:300' rel='stylesheet' type='text/css'>
</head>
<body>

<h1>Welcome, please login to your account.</h1>

<form action="index.php" method="POST">

    <input type="text" placeholder = "Username" name="username">
    <input type="password" placeholder = "Password" name="password">
    <input type="submit" value="Login">
</form> 

<div class="footer">
<p>roleplay factory &copy; 2016 all rights reserved</p>
</div>

</body>
</html>

Answer 1

您创建了之后的全局变量$ _COOKIE（其中包含PHP通过HTTP请求收到的Cookie信息）填充了数据，因此您无法访问它。

检查cookie是否存在。如果没有，它首先登录并输出值。

if ( isset( $_COOKIE[ "login" ] ) ) { // your original line of code echo "You are now logged in with hash: ".htmlspecialchars($_COOKIE["login"]). '<a href="index.php?logout=1">logout</a>?'; } else { echo "You are now logged in with hash: ".htmlspecialchars($session). '<a href="index.php?logout=1">logout</a>?'; }

Answer 2

第39行，如错误消息所示，如下所示：

echo "You are now logged in with hash: ".htmlspecialchars($_COOKIE["login"]). '<a href="index.php?logout=1">logout</a>?';

您不会检查是否设置了$_COOKIE["login"]。

PHP中的cookie和会话

2 个答案: