我有一个HTML登录表单，该表单的操作将发送到另一个PHP文件，该文件中应有一个用于将用户登录到该站点的功能。当提交表单导致该php文件时，它显示一个空白页面，就像它不会触发该函数一样。我在函数顶部放置了echo和die，但是仍然没有任何反应。
此外，当我在函数外部回显某些内容时，它还会显示我在echo中输入的内容，因此它会调用正确的文件，只是不会加载函数。任何帮助表示赞赏。这是我的代码。
login.php
<?php
if ($_SERVER['REQUEST_METHOD'] == "POST") {
if (isset($_POST["submit"])) {
login_function();
}
}
?>
<!DOCTYPE HTML>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Welcome to Love Her Feet</title>
<meta name="viewport" content="width=device-width,initial-scale=1.0">
<link rel="stylesheet" href="/login_assets/css/style.css">
<link href="https://fonts.googleapis.com/css?family=Raleway:300,400,500&display=swap" rel="stylesheet">
<link href="https://fonts.googleapis.com/css?family=Open+Sans:400,600&display=swap" rel="stylesheet">
<link rel="stylesheet" href="/login_assets/css/media.css">
<script src="/login_assets/js/jquery.min.js"></script>
<script src="/login_assets/js/modernizr.custom.js"></script>
</head>
<body>
<header class="clear hBlack">
<div class="jLogo"><a href="/"><img src="/login_assets/images/logo.png" alt=""></a></div>
</header>
<div class="logArea clear">
<form action="custom_functions.php" method="post" enctype="application/x-www-form-urlencoded">
<div class="logbox">
<div class="box clear">
<h2>Members Area</h2>
<div class="logTypes">
<input type="text" name="username" class="logtextbox" placeholder="username or email">
<span class="text-danger"><?php echo $username_error; ?></span>
<input type="password" name="password" class="logtextbox" placeholder="Password"><br>
<span class="text-danger"><?php echo $password_error; ?></span>
<!-- <input type="text" name="captcha" class="logtextbox" placeholder="Enter the code shown below"><br>
<img style="margin: 0 auto;" src="captcha.php">
<span class="text-danger"><?php echo $captcha_error; ?></span> -->
<div style="text-align: center">Remember my login: <input name="remember" type="checkbox"></div>
</div>
</div>
<input type="submit" value="submit" class="logBtn" name="submit"/>
</div>
</form>
</div>
<footer class="clear">
<p class="fNav"><a href="/">Home</a><span>|</span>
<a href="/">Log Out</a>
</p>
</footer>
</body>
</html>
custom_functions.php
<?php
//echo "AAAAAAAAA";
function validation($form_data)
{
$form_data = trim(stripcslashes(htmlspecialchars($form_data)) );
return $form_data;
}
function login_function() {
//echo "AAAAAAAAAA";
//die('!');
session_start();
require 'connection.php';
$username_error = "";
$password_error = "";
//$captcha_error = "";
$v_username = $_POST['username'];
$v_password = $_POST['password'];
//$v_captcha = $_POST['captcha'];
$username = validation($v_username);
$password = validation($v_password);
//$captcha = validation($v_captcha);
$remember = isset($_POST['remember']);
if (empty($username)) {
$username_error = "<p>Please enter your username!</p>";
}
if (empty($password)) {
$password_error = "<p>Please enter your password!</p>";
}
if (!empty($username) && !empty($password)) {
$sql = "SELECT * FROM member_auth WHERE username = :username";
//$sql = "SELECT * FROM member_auth LIMIT 1";
$stmt = $pdo->prepare($sql);
$stmt->bindValue(':username',$username);
$stmt->execute();
$user = $stmt->fetch(PDO::FETCH_ASSOC);
$cryptpass = $user['cryptpass'];
if($user === false){
$username_error = "<p>User doesn't exist</p>";
} elseif ($user) {
$newPass = crypt($password,$cryptpass);
if ($cryptpass == $newPass) {
$_SESSION['loggedin'] = TRUE;
$_SESSION['username'] = $username;
if ($remember == "on") {
setcookie("remember",$username,time()+3600);
}
header('Location: login_success.php');
} else {
$password_error = "<p>Password is not correct!</p>";
}
}
}
}
?>