//定义前台视图路径常量
define('HOME_VIEW_DIR', 'views/Home/');
//定义后台视图路径常量
define('ADMIN_VIEW_DIR', 'views/Pkadmin/');
//版本
define('PKADMIN_VERSION', '1.0.0');

<?php
/**
 * ==========================================
 * Created by Pocket Knife Technology.
 * Author: ZhiHua_W <zhihua_wei@foxmail.com>
 * Date: 2016/11/02 0031
 * Time: 上午 9:19
 * Project: Pkadmin后台管理系统
 * Version: 1.0.0
 * Power: 加载器扩展
 * ==========================================
 */
defined('BASEPATH') OR exit('No direct script access allowed');
class PK_Loader extends CI_Loader {
 /**
  * 设置前台视图路径
  */
 public function set_home_view_dir() {
  $this -> _ci_view_paths = array(APPPATH . HOME_VIEW_DIR => TRUE);
 }
 /**
  * 设置后台视图路径
  */
 public function set_admin_view_dir() {
  $this -> _ci_view_paths = array(APPPATH . ADMIN_VIEW_DIR => TRUE);
 }
}

<?php
/**
 * ==========================================
 * Created by Pocket Knife Technology.
 * Author: ZhiHua_W <zhihua_wei@foxmail.com>
 * Date: 2016/11/02 0031
 * Time: 上午 9:23
 * Project: Pkadmin后台管理系统
 * Version: 1.0.0
 * Power: 控制器扩展
 * ==========================================
 */
defined('BASEPATH') OR exit('No direct script access allowed');
/**
 * 前台父控制器
 */
class Home_Controller extends CI_Controller {
 public function __construct() {
  parent::__construct();
  $this -> load -> set_home_view_dir();
 }
}
/**
 * 后台父类控制器
 */
class Pkadmin_Controller extends CI_Controller {
 public $data;
 public function __construct() {
  parent::__construct();
  $this -> load -> set_admin_view_dir();
 }
}

<?php
/**
 * ==========================================
 * Created by Pocket Knife Technology.
 * Author: ZhiHua_W <zhihua_wei@foxmail.com>
 * Date: 2016/11/05 0015
 * Time: 上午 10:23
 * Project: Pkadmin后台管理系统
 * Version: 1.0.0
 * Power: 后台主页控制器
 * ==========================================
 */
defined('BASEPATH') OR exit('No direct script access allowed');
class Admin extends Pkadmin_Controller {
 public function __construct() {
  parent::__construct();
  $this -> load -> model('login_model', 'admin');
  $this -> load -> library('pagination');
 }
 /**
  * Pkadmin 后台首页action
  */
 public function index() {
  $this -> load -> view('admin.html', $data);
 }
}