CodeIgniter分页不起作用（在其他页面中）

I'm new in php, and in CI as well. I'm creating my own web application, and i've encountered an issue with pagination.

My main pagination on index is working as charm without problems, but if i init the pagination in other pages, it shows links as well as the pagination, but when i click, the page refreshes wish /6 (content per page) showing same stuff that have been generated from the database.

That is the code i use in function index:

public function index($offset = 0){
        $config['base_url'] = base_url() . '/usernames/index/';
        $config['total_rows'] = $this->db->count_all('usernames');
        $config['per_page'] = 6;
        $config['uri_segment'] = 3;

        $config['full_tag_open'] = '<ul class="pagination justify-content-center">';
        $config['full_tag_close'] = '</ul>';
        $config['attributes'] = ['class' => 'page-link'];
        $config['first_link'] = false;
        $config['last_link'] = false;
        $config['first_tag_open'] = '<li class="page-item">';
        $config['first_tag_close'] = '</li>';
        $config['prev_link'] = 'Previous';
        $config['prev_tag_open'] = '<li class="page-item">';
        $config['prev_tag_close'] = '</li>';
        $config['next_link'] = 'Next';
        $config['next_tag_open'] = '<li class="page-item">';
        $config['next_tag_close'] = '</li>';
        $config['last_tag_open'] = '<li class="page-item">';
        $config['last_tag_close'] = '</li>';
        $config['cur_tag_open'] = '<li class="page-item active"><a href="#" class="page-link">';
        $config['cur_tag_close'] = '<span class="sr-only">(current)</span></a></li>';
        $config['num_tag_open'] = '<li class="page-item">';
        $config['num_tag_close'] = '</li>';
        $config['attributes'] = array('class' => 'page-link');

        $this->pagination->initialize($config);

        $data['title'] = 'Lastest Usernames';

        $data['posts'] = $this->post_model->get_usernames(FALSE, $config['per_page'], $offset);

        $this->load->view('templates/header');
        $this->load->view('usernames/index', $data);
        $this->load->view('templates/footer');
    }

This is what i'm using in function snapchat:

public function snapchat($offset = 0){
        $config['base_url'] = base_url() . '/usernames/snapchat/';
        $config['total_rows'] = $this->db->count_all('usernames');
        $config['per_page'] = 6;
        $config['uri_segment'] = 3;

        $config['full_tag_open'] = '<ul class="pagination justify-content-center">';
        $config['full_tag_close'] = '</ul>';
        $config['attributes'] = ['class' => 'page-link'];
        $config['first_link'] = false;
        $config['last_link'] = false;
        $config['first_tag_open'] = '<li class="page-item">';
        $config['first_tag_close'] = '</li>';
        $config['prev_link'] = 'Previous';
        $config['prev_tag_open'] = '<li class="page-item">';
        $config['prev_tag_close'] = '</li>';
        $config['next_link'] = 'Next';
        $config['next_tag_open'] = '<li class="page-item">';
        $config['next_tag_close'] = '</li>';
        $config['last_tag_open'] = '<li class="page-item">';
        $config['last_tag_close'] = '</li>';
        $config['cur_tag_open'] = '<li class="page-item active"><a href="#" class="page-link">';
        $config['cur_tag_close'] = '<span class="sr-only">(current)</span></a></li>';
        $config['num_tag_open'] = '<li class="page-item">';
        $config['num_tag_close'] = '</li>';
        $config['attributes'] = array('class' => 'page-link');

        $this->pagination->initialize($config);

        $data['title'] = 'Lastest Snapchat Usernames';

        $data['posts'] = $this->post_model->get_usernames(FALSE, $config['per_page'], $offset);
        $filter = "Snapchat";
        $filteredData = $this->post_model->get_snapchat($filter);

        $data=[
            'F_username' => $filteredData->result_array()
        ];

          $this->load->view('templates/header');
          $this->load->view('usernames/snapchat', $data);
          $this->load->view('templates/footer');
    }

This is the code i'm using in model:

public function get_snapchat($filter, $slug = FALSE, $limit = FALSE, $offset = FALSE){
        if ($limit) {
            $this->db->limit($limit ,$offset);
        }
        $filter = "Snapchat";

        $query = $this->db->get_where('usernames', array('platform' => $filter));
        return $query;
    }

This is the simples step :

1. Create pagination.php in application/config to separate pagination config from your Controller (https://gist.github.com/mikedfunk/3504432)

2. Models :

/* Your_model.php */
// -------------------

// Get Data With Limit
public function data($start, $limit) {

  return $this->db->from('TABLE_NAME')
                  ->limit($start, $limit)
                  ->get();
}

// Total All Rows
public function total() {

  return $this->db->count_all_results('TABLE_NAME');
}

// Get First Records
public function first_record($current_page, $per_page) {

  return ($current_page - 1) * $per_page;
}

3. Controller :

/* Your_controller.php */
// -------------------

public function output() {

  // Library
  $this->load->library('pagination');

  // Pagination Config
  $config['base_url'] = site_url('Your/Controller');
  $config['per_page'] = 30;
  $config['uri_segment'] = 3;

  // Starting
  $curpage = $this->uri->segment(3);
  $start = $this->your_model->first_record($curpage, $config['per_page']);
  $limit = $config['per_page'];

  // Get Result
  $data['result'] = $this->your_model->data($start, $limit);

  // Get Total Records
  $config['total_rows'] = $this->your_model->total();

  // Process Pagination
  $this->pagination->initialize($config);

  // Prep Data
  $data['navigation'] = $this->pagination->create_links();

  // Load View (Passing $result & $navigation data)
  $this->layout->view('YOUR_VIEW_HERE', $data);

}

You need adjust to your database config :)