PHP提交按钮没有响应（Codeigniter）

我有以下视图（home\u view.php）

diluks电子商务-主页
没有输入类型。你必须提到输入的类型

<input type="submit" name="btn_read" class="readbtn" value="Read More" />



<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class Welcome_controller extends CI_Controller {

function __construct(){
        parent::__construct();


    }

    public function index()
    {
        if(isset($_POST["btn_login"])){
          $data = array();
            $this->load->model('category_model');
            $data['categories'] = $this->category_model->getCategories();

          $this->load->view('login_view', $data);
        }
        else if(isset($_POST["btn_adminpanel"])){

          $this->load->view('adminpanel_view');
        }
        else if(isset($_POST["btn_logout"])){

          $this->session->sess_destroy();
          $data = array();
            $this->load->model('category_model');
            $data['categories'] = $this->category_model->getCategories();
            $this->load->view('home_view', $data);
        }
        else if(isset($_POST["btn_read"])){

            $this->load->view('readmore_view');

        }

    }


}

<input type="submit" name="btn_read" class="readbtn" value="Read More" />