Codeigniter getinstance()错误,未加载任何库、助手


Codeigniter getinstance() error not loading any library,helpers?

我正在codeigniter中创建一个登录系统。我是代码点火器的新手。我在测试我的登录系统时遇到了这个错误

    A PHP Error was encountered
Severity: Notice
Message: Trying to get property of non-object
Filename: controllers/login.php
Line Number: 92
Fatal error: Call to a member function userdata() on a non-object in P:'xampp'htdocs'xxxxx'xxxxx'application'controllers'login.php on line 92

这是我的login.php控制器文件

<?php
class Login extends CI_Controller {
    function __construct()
    {
        if($this->is_logged_in() === true){
            redirect('welcome');
        }
    }
    function index()
    {
        $data['main_content'] = 'login_form';
        $data['class_name'] = get_class();
        $data['no_header'] = '1';
        $data['no_footer'] = '1';
        $this->load->view('includes/template', $data);      
    }
    function validate_credentials()
    {       
        $this->load->model('admin_model');
        $query = $this->admin_model->validate();
        print_r($query);
        if($query) // if the user's credentials validated...
        {
            $data = array(
                'AdminID' => $query,
                'is_logged_in' => true
            );
            $this->session->set_userdata($data);
            redirect('welcome');
        }
        else // incorrect username or password
        {
            echo "here";
            exit;
            $this->index();
        }
    }   
    function signup()
    {
        $data['main_content'] = 'signup_form';
        $this->load->view('includes/template', $data);
    }
    function create_member()
    {
        $this->load->library('form_validation');
        // field name, error message, validation rules
        $this->form_validation->set_rules('first_name', 'Name', 'trim|required');
        $this->form_validation->set_rules('last_name', 'Last Name', 'trim|required');
        $this->form_validation->set_rules('email_address', 'Email Address', 'trim|required|valid_email');
        $this->form_validation->set_rules('username', 'Username', 'trim|required|min_length[4]');
        $this->form_validation->set_rules('password', 'Password', 'trim|required|min_length[4]|max_length[32]');
        $this->form_validation->set_rules('password2', 'Password Confirmation', 'trim|required|matches[password]');

        if($this->form_validation->run() == FALSE)
        {
            $this->load->view('signup_form');
        }
        else
        {           
            $this->load->model('membership_model');
            if($query = $this->membership_model->create_member())
            {
                $data['main_content'] = 'signup_successful';
                $this->load->view('includes/template', $data);
            }
            else
            {
                $this->load->view('signup_form');           
            }
        }
    }
    function logout()
    {
        $this->session->sess_destroy();
        $this->index();
    }
    function is_logged_in()
    {
        $CI =&get_instance();
        $is_logged_in = $CI->session->userdata('is_logged_in');
        if(isset($is_logged_in) || $is_logged_in === true)
        {
            return true;
        }else{
            return false;
        }
    }
}

我试过

$CI =&get_instance();
$CI =get_instance();
$this->session->userdata

三种方式都有,但都出错了。

您在Controller的构造函数中调用is_logged_in()函数,而不首先调用父构造函数。也许这就是为什么有些资源还没有加载的原因。

尝试添加以下内容:

function __construct()
{
    parent::__construct(); //you always have to call parent's constructor before ANYTHING
    if($this->is_logged_in() === true){
        redirect('welcome');
    }
}

您没有为使用get_instance()创建的实例加载会话库。

简单地说,假设会话已经加载,并且正如@jere所指出的,您在控制器中调用父级::__construct():

function is_logged_in()
{
    $is_logged_in = $this->session->userdata('is_logged_in');
    if(isset($is_logged_in) || $is_logged_in === true)
    {
        return true;
    }else{
        return false;
    }
}

不知道为什么在这里使用该类的另一个实例。

如果你应该这样做,试着再次加载会话库,比如:

$CI->load->library('session')
$is_logged_in = $CI->session->userdata('is_logged_in');
//rest of your old code