警告:正在尝试访问布尔类型值的数组偏移量

Question

登录表单运行良好，但当我输入错误的用户名时，会出现错误

警告：试图访问bool 类型值的数组偏移量

我有一个登录表单，代码为：

<?php
include('class.password.php');
class User extends Password{
private $db;
function __construct($db){
parent::__construct();
$this->_db = $db;
}
public function is_logged_in(){
if(isset($_SESSION['loggedin']) && $_SESSION['loggedin'] == true){
return true;
}
}
private function get_user_hash($username){
try {
$stmt = $this->_db->prepare('SELECT MemberID, username, password FROM admins WHERE username = :username');
$stmt->execute(array('username' => $username));
return $stmt->fetch();
} catch(PDOException $e) {
echo '<p class="error">'.$e->getMessage().'</p>';
}
}

public function login($username,$password){
$user = $this->get_user_hash($username);
if($this->password_verify($password,$user['password']) == 1){
$_SESSION['loggedin'] = true;
$_SESSION['memberID'] = $user['memberID'];
$_SESSION['username'] = $user['username'];
return true;
}
}

public function logout(){
session_destroy();
}
}

?>

这就是出现错误的原因：

if($this->password_verify($password,$user['password']) == 1){

Answer 1

问题是，当没有提供用户名的用户时，get_user_hash方法将返回false。您应该考虑将代码更改为：

if(!empty($user) && $this->password_verify($password,$user['password']) == 1){