我建议您改变方法。
尽管乍看之下这些示例文件看起来很多，但是一旦研究它们，您会发现它实际上比现在的方向更加简单和合乎逻辑。
首先，将db connect / login内容移到一个单独的文件中，
require或
include将该文件移到每个PHP页面的顶部：
初始化PHP
// Create connection $conn = new mysqli($servername, $username, $password, $db); // Check connection if ($conn->connect_error) { die("Connection failed: " . $conn->connect_error); } //Might as well also load your functions page here, so they are always available require_once('fn/functions.php');?>现在，在“索引（和受限）”页面上查看我们如何使用它？
索引文件
<?php require_once('inc/head.inc.php'); require_once('fn/init.php');?><body> <!-- Examples need jQuery, so load that... --> <script src="https://pre.jquery.com/jquery-1.11.3.js"></script> <!-- and our own file we will create next... --> <script type="text/javascript" src="js/index.js"></script> <div id="pageWrap"> <div id="loginDIV"> LoginID: <input type="text" id="liID" /><br> LoginPW: <input type="password" id="liPW" /><br> <input type="button" id="myButt" value="Login" /> </div> </div>JS / INDEX.JS
$(function(){ $('#myButt').click(function(){ var id = $('#liID').val(); var pw = $('#liPW').val(); $.ajax({ type: 'post', url: 'ajax/login.php', data: 'id=' +id+ '&pw=' +pw, success: function(d){ if (d.length) alert(d); if (d==1) { window.location.href = 'restricted_page.php'; }else{ $('#liID').val(''); $('#liPW').val(''); alert('Please try logging in again'); } } }); });//END myButt.click}); //END document.readyAJAX /登录
<?php $id = $_POST['id']; $pw = $_POST['pw']; //Verify from database that ID and PW are okay //Note that you also should sanitize the data received from user if ( id and password authenticate ){ //Use database lookups ot get this data: $un = `username` //Use PHP sessions to set global variable values $_SESSION['username'] = $un; echo 1; }else{ echo 'FAIL'; }RESTRICTED_PAGE.PHP
<?php if (!isset($_SESSION['username']) ){ header('Location: ' .'index.php'); } require_once('inc/head.inc.php'); require_once('fn/init.php');?><body> <h1>Welcome to the Admin Page, <?php echo $_SESSION['username']; ?> <!-- AND here go all teh restricted things you need a login to do. -->
