无法修改 header 信息 - header 已在 php 邮件程序中发送

Question

我正在编码基于令牌的用户密码验证，当用户单击重置按钮时，密码验证 link 会发送到用户电子邮件帐户，当用户在电子邮件中单击验证 link 时，用户使用用户名和密码登录，在我的代码中一切正常，我的消息也被发送，但是这个错误消息也在我的新 window 页面中生成。我正在本地发送这封电子邮件，然后将其发送到 xampp 服务器。

php:

  <?php 
session_start();
require_once("db.php");
//if user click submit button
if(isset($_POST['submit']))
{
     //escape special charater in string first
    $email = $conn->real_escape_string($_POST['email']);

    // query to check if email already exists or not
    $sql = "SELECT email FROM user WHERE email='$email'";
    $result = $conn->query($sql);
    if($result->num_rows > 0)
    {
        $newToken = rand(100000000, 999999999);
        //encrypt the token
        $token = base64_encode(strrev(md5($newToken)));
        //$token = $newToken;
        //new register token
         $sql1 = "UPDATE user SET token='$token',tokenExpire=DATE_ADD(NOW(),INTERVAL 1 HOUR) WHERE email='$email'";
        if($conn->query($sql1) === TRUE)
        {
            //send mail
            require '../phpmailer/PHPMailerAutoload.php';
            if(!filter_var($email,FILTER_VALIDATE_EMAIL))
            {
            //SHOW ERROR MESSAGE
            }
            else
            {

             $mail = new PHPMailer(true);                              // Passing `true` enables exceptions

             //Server settings
             $mail->SMTPDebug = 2;                                 // Enable verbose debug output
             $mail->isSMTP();                                      // Set mailer to use SMTP
             $mail->Host = 'smtp.Gmail.com';                       // Specify main and backup SMTP servers

             $mail->SMTPOptions = array(
                  'ssl'=>array(
                   'verify_peer'=>false,
                   'verify_peer_name'=>false,
                    'allow_self_signed'=>true   
)                  
);
             $mail->SMTPAuth = true;                               // Enable SMTP authentication
             $mail->Username = 'luckynath4@gmail.com';                 // SMTP username
             $mail->Password = 'secretpassword';                           // SMTP password
             $mail->SMTPSecure = 'tls';                            // Enable TLS encryption, `ssl` also accepted
             $mail->Port = 587;                                    // TCP port to connect to

             //Recipients
             $mail->setFrom("luckynath4@gmail.com","Hiring Top");
             $mail->addAddress($email,"User");                       // Add a recipient


             //Content
             $mail->isHTML(true);                                  // Set email format to HTML
             $mail->Subject = 'Hiring Top-Password Reset Message';
             $mail->Body    = '<!DOCTYPE html>
              <html>
              <head>
                <title>Password Reset</title>
              </head>
              <body>
               Hi,<h3>'.$_POST['email'].'</h3>
                <p>We recieved a password reset request</p>
               <p> In order to reset your password, please click on the link below,</p>
                <p>if you did not make this request,you can ignore this mail.</p>
               <a href="http://localhost/practise/job_portal_theme/verify1.php?token='.$token.'&email='.$email.'">verify your password</a>
               <p>Thanks.</p><br />
               <p>message from Hiring Top team.</p>

              </body>
              </html>';
              if( $mail->send())
              {
                $_SESSION['checkEmail'] = true;
                header("Location:forgot_password.php");
                exit();
              }
              else
              {
                echo 'Mailer error: ' . $mail->ErrorInfo;
              } 

            }

        }
        else
        {
            //If data failed to insert then show that error.  
            echo "Error:" .$sql.$conn->error;
        }




    }
    else
    {
        //if email not found in database
        $_SESSION['emailNotFoundError']=true;
        header("Location:forgot_password.php");
        exit();
    }   

 $conn->close();
}
else
{
//redirect them back to forgot-password.php page if they didn't click Forgot Password button    
header("Location:forgot_password.php");
exit();
}
?>

Answer 1

No output before sending headers

send/modify HTTP headers 必须在进行任何输出之前调用的功能。否则调用失败：

see detail here

OR

试试这个

使用window.location代替header

echo "<script>window.location.assign('forgot_password.php')</script>";

Answer 2

send/modify HTTP header 必须在进行任何输出之前调用的功能。否则调用失败：

警告：无法修改 header 信息 - header 已发送（输出从 file:line 开始）一些修改 HTTP header 的函数是：

header / header_remove session_start / session_regenerate_id setcookie / setrawcookie 输出可以是：

无意：之前的空格 UTF-8 字节序标记以前的错误消息或通知故意的： print、echo 和其他产生输出的函数（如 var_dump）之前的原始区域

Answer 3

我每次使用这条线时都会遇到这种情况

header("Location:forgot_password.php");

试试这个：

echo '<script type="text/javascript">window.location = "domain.com/forgot_password.php"</script>';

无法修改 header 信息 - header 已在 php 邮件程序中发送

Cannot modify header information - headers already sent in php mailer

phpmailer