CodeIgniter问题：登录后查看记录出现404页面未找到

Hey there! Let's work through this 404 issue you're hitting as a new CodeIgniter developer. I remember dealing with similar headaches when I started, so let's break down the most common fixes step by step.

1. Double-Check Your Route Configuration #

CodeIgniter relies on the application/config/routes.php file to map URLs to your controller methods. If your admin records page isn't routing correctly, you'll get a 404 every time.

For example, if your admin records are handled by an Admin controller and a view_all_records method, add this line to your routes:

$route['admin/records'] = 'admin/view_all_records';

• Make sure the URL segment (admin/records) matches what you're linking to in your header.
• Remember: CodeIgniter is case-sensitive by default—so Admin.php (controller filename) and class Admin extends CI_Controller must match exactly.

2. Verify Your Controller & Method Exist #

First, confirm your Admin.php controller is in the application/controllers folder. Inside it, you need the method to load your records, plus session validation to ensure only logged-in admins can access it:

class Admin extends CI_Controller {
    public function __construct() {
        parent::__construct();
        // Block access if user isn't logged in
        if (!$this->session->userdata('logged_in')) {
            redirect('users/login');
        }
    }

    public function view_all_records() {
        // Fetch your records here (replace with your model logic)
        $data['records'] = $this->record_model->get_all_records();
        
        // Load your template files
        $this->load->view('header');
        $this->load->view('admin/records_view', $data);
        $this->load->view('footer');
    }
}

Also, check that your server has read permissions for the controller file—sometimes file permissions can silently cause 404s.

3. Fix the URL Link in Your Header #

Looking at your header snippet, your login link uses base_url(), so your admin link should follow the same pattern. Make sure you're generating the correct URL that matches your route:

<li class="nav-item">
    <a class="nav-link" href="<?php echo base_url('admin/records'); ?>">View All Records</a>
</li>

Don't forget to set your base_url correctly in application/config/config.php:

$config['base_url'] = 'http://your-website-url.com/'; // Replace with your actual domain

If base_url is empty, CodeIgniter might generate broken paths that lead to 404s.

4. Check Your .htaccess (If Using URL Rewriting) #

If you're trying to remove index.php from your URLs, a misconfigured .htaccess is a common culprit. Here's a standard working configuration:

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php/$1 [L]

Also, ensure application/config/config.php has:

$config['index_page'] = '';

If .htaccess is missing or incorrect, CodeIgniter won't parse your URLs properly.

5. Debug with Logs #

If none of the above fixes work, turn on CodeIgniter's logging to get more details. In application/config/config.php:

$config['log_threshold'] = 2; // Logs errors and messages

Then visit the 404 page, and check the application/logs folder for the latest log file. It will tell you exactly which controller/method CodeIgniter is trying to find (and failing to locate).

If you can share more code (like your full header.php, routes, or admin controller), I can help narrow it down even further. But start with these steps—they solve 90% of CodeIgniter 404 issues for new devs.

内容的提问来源于stack exchange，提问作者Harun Anwar