PHP-setcookie（）; 不工作

Question

我进行了登录，设置了一个带有估算电子邮件地址值的cookie，因此在global.php文件中，它使用以下命令存储用户数据数组：

$email = $_COOKIE["PeopleHub"];
$getuserdata = mysqli_query($con, "SELECT * FROM Earth WHERE email='$email'");
$userdata = mysqli_fetch_array($getuserdata, MYSQLI_ASSOC);

cookie尚未设置，我知道这是因为我做了一个测试文件：

echo $_COOKIE["PeopleHub"];

它只是做了一个空白页。

登录代码（设置cookie的位置）：

<?php 
include "global.php";    
?>
<h2>Login</h2>
<?php 
    echo "We currently have <b>" . $usercount . "</b> members, <b>" . $onlinecount . "</b> of which are online. "; 
?>
<br>
<br>
<?php 
    if(isset($_POST["email"])){ 
        $email = $_POST["email"];
        $password = sha1($_POST["password"]);
        $check = mysqli_query($con, "SELECT * FROM Earth WHERE `email`='$email' AND `password`='$password'");
        $check = mysqli_num_rows($check);
        if($check == 1){
        setcookie("PeopleHub", $email, 0, '/');
        echo "We logged you in!";
        }
        else { 
            echo "We couldn't log you in!";
        }
    }
?>
<form action="<?php echo $_SERVER['REQUEST_URI']; ?>" method="post">
    Email <input name="email" placeholder="Email Address" required="" type="text"><br>
    Password <input name="password" placeholder="Password" required="" type="password"><br>
    <input type="reset" value="Start Over">
    <input type="submit" value="Login">
</form>

Answer 1

您必须先设置Cookie， 然后再 发送任何标头。

从手册：

setcookie（）定义要与其他HTTP标头一起发送的cookie。与其他标头一样，必须在脚本的任何输出之前发送cookie（这是协议限制）。这要求您在所有输出（包括和标记以及任何空格）之前都先调用此函数。

这意味着如果您希望按原样使用此代码，则需要研究输出缓冲。

<?php

ob_start();
echo "Hello\n";

setcookie("cookiename", "cookiedata");

ob_end_flush();

?>

根据的内容global.php，这 可能
适合您。我所做的只是在setcookie()调用之前删除了所有输出。如果global.php其中包含任何空格或HTML输出，则将不起作用：

<?php 
include "global.php";

    if(isset($_POST["email"])){ 
        $email = $_POST["email"];
        $password = sha1($_POST["password"]);
        $check = mysqli_query($con, "SELECT * FROM Earth WHERE `email`='$email' AND `password`='$password'");
        $check = mysqli_num_rows($check);
        if($check == 1){
        setcookie("PeopleHub", $email, 0, '/');
        echo "We logged you in!";
        }
        else { 
            echo "We couldn't log you in!";
        }
    }
?>
<h2>Login</h2>
<?php 
    echo "We currently have <b>" . $usercount . "</b> members, <b>" . $onlinecount . "</b> of which are online. "; 
?>
<br>
<br>
<form action="<?php echo $_SERVER['REQUEST_URI']; ?>" method="post">
    Email <input name="email" placeholder="Email Address" required="" type="text"><br>
    Password <input name="password" placeholder="Password" required="" type="password"><br>
    <input type="reset" value="Start Over">
    <input type="submit" value="Login">
</form>