如何在 PHP 7 中从页面重定向到页面？

Question

我正在用 PHP 7 和 HTML 5 制作一个电子商务网站。当我输入登录详细信息时，admin.php 只是刷新并且不会重定向到 index.php，因为它应该。

我已经尝试过使用实际的 cookie，但出于安全原因我更愿意只使用会话 cookie。

ADMIN LOGIN.php CODE

<?php

session_start();

if(isset($_SESSION["manager"])){

  header("location: index.php");

  exit();

}

?>

<?php

if (isset($_POST["username"])&&isset($_POST["password"])){

  $manager = preg_replace('#[^A-Za-z0-9]#i', '', $_POST["username"]);

  $password = preg_replace('#[^A-Za-z0-9]#i', '', $_POST["password"]);

  include "../storescripts/connect_to_mysql.php";

  //$sqlquery =

  $sql = mysqli_query($con, "SELECT id FROM admin WHERE username='$manager' AND password='$password' LIMIT 1");

  $existCount=mysqli_num_rows($sql);

  if($existCount == 1){

    while($row = mysqli_fetch_array($sql)){

      $id = $row["id"];

    }

    $_SESSION["id"] = $id;

    $_SESION["manager"] = $manager;

    $_SESSION["password"] = $password;

    header("location: index.php");

    exit();

  } else {

    // code...

    echo 'Invalid Log In Credentials<br><br>';

    echo'<a href="index.php">Click Here To Re-Enter Credentials</a>';

    exit();

  }

}

?>

INDEX.php CODE

<?php

session_start();

if (!isset($_SESSION["manager"])){

  header("location: admin_login.php");

  exit();

}

$managerID = preg_replace('#[^0-9]#i', '', $_SESSION["id"]);

$manager = preg_replace('#[^A-Za-z0-9]#i', '', $_SESSION["manager"]);

$password = preg_replace('#[^A-Za-z0-9]#i', '', $_SESSION["password"]);

include "../storescripts/connect_to_mysql.php";

$sql = mysqli_query($con, "SELECT * FROM admin WHERE id='$managerID' AND     username='$manager' AND password='$password' LIMIT 1");

$existCount = mysqli_num_rows($sql);

if ($existCount == 0){

  header("location: ../index.php");

  exit();

}

?>

一旦设置了会话 cookie，我希望页面重定向到 index.php，但它没有这样做。