'user'=>array(
  'class'=>'WebUser',//这个WebUser是继承CwebUser，稍后给出它的代码
  'stateKeyPrefix'=>'member',//这个是设置前台session的前缀
  'allowAutoLogin'=>true,//这里设置允许cookie保存登录信息，一边下次自动登录
),

<?php
class AdminModule extends CWebModule
{
  public function init()
  {
    // this method is called when the module is being created
    // you may place code here to customize the module or the application
    parent::init();//这步是调用main.php里的配置文件
    // import the module-level models and componen
    $this->setImport(array(
      'admin.models.*',
      'admin.components.*',
    ));
    //这里重写父类里的组件
    //如有需要还可以参考API添加相应组件
    Yii::app()->setComponents(array(
        'errorHandler'=>array(
            'class'=>'CErrorHandler',
            'errorAction'=>'admin/default/error',
        ),
        'admin'=>array(
            'class'=>'AdminWebUser',//后台登录类实例
            'stateKeyPrefix'=>'admin',//后台session前缀
            'loginUrl'=>Yii::app()->createUrl('admin/default/login'),
        ),
    ), false);
    //下面这两行我一直没搞定啥意思，貌似CWebModule里也没generatorPaths属性和findGenerators()方法
    //$this->generatorPaths[]='admin.generators';
    //$this->controllerMap=$this->findGenerators();
  }
  public function beforeControllerAction($controller, $action)
  {
    if(parent::beforeControllerAction($controller, $action))
    {
      $route=$controller->id.'/'.$action->id;
      if(!$this->allowIp(Yii::app()->request->userHostAddress) && $route!=='default/error')
        throw new CHttpException(403,"You are not allowed to access this page.");
      $publicPages=array(
        'default/login',
        'default/error',
      );
      if(Yii::app()->admin->isGuest && !in_array($route,$publicPages))
        Yii::app()->admin->loginRequired();
      else
        return true;
    }
    return false;
  }
  protected function allowIp($ip)
  {
    if(empty($this->ipFilters))
      return true;
    foreach($this->ipFilters as $filter)
    {
      if($filter==='*' || $filter===$ip || (($pos=strpos($filter,'*'))!==false && !strncmp($ip,$filter,$pos)))
        return true;
    }
    return false;
  }
}
?>

/**
* Clears all user identity information from persistent storage.
 * This will remove the data stored via {@link setState}.
 */
public function clearStates()
{
  $keys=array_keys($_SESSION);
  $prefix=$this->getStateKeyPrefix();
  $n=strlen($prefix);
  foreach($keys as $key)
  {
    if(!strncmp($key,$prefix,$n))
      unset($_SESSION[$key]);
  }
}

Yii::app()->user //前台访问用户信息方法
Yii::app()->admin //后台访问用户信息方法

<?php
class WebUser extends CWebUser
{
  public function __get($name)
  {
    if ($this->hasState('__userInfo')) {
      $user=$this->getState('__userInfo',array());
      if (isset($user[$name])) {
        return $user[$name];
      }
    }
    return parent::__get($name);
  }
  public function login($identity, $duration) {
    $this->setState('__userInfo', $identity->getUser());
    parent::login($identity, $duration);
  }
}
?>

<?php
class AdminWebUser extends CWebUser
{
  public function __get($name)
  {
    if ($this->hasState('__adminInfo')) {
      $user=$this->getState('__adminInfo',array());
      if (isset($user[$name])) {
        return $user[$name];
      }
    }
    return parent::__get($name);
  }
  public function login($identity, $duration) {
    $this->setState('__adminInfo', $identity->getUser());
    parent::login($identity, $duration);
  }
}
?>

<?php
/**
 * UserIdentity represents the data needed to identity a user.
 * It contains the authentication method that checks if the provided
 * data can identity the user.
 */
class UserIdentity extends CUserIdentity
{
  /**
   * Authenticates a user.
   * The example implementation makes sure if the username and password
   * are both 'demo'.
   * In practical applications, this should be changed to authenticate
   * against some persistent user identity storage (e.g. database).
   * @return boolean whether authentication succeeds.
   */
  public $user;
  public $_id;
  public $username;
  public function authenticate()
  {
    $this->errorCode=self::ERROR_PASSWORD_INVALID;
    $user=User::model()->find('username=:username',array(':username'=>$this->username));
     if ($user)
    {
      $encrypted_passwd=trim($user->password);
      $inputpassword = trim(md5($this->password));
      if($inputpassword===$encrypted_passwd)
      {
        $this->errorCode=self::ERROR_NONE;
        $this->setUser($user);
        $this->_id=$user->id;
        $this->username=$user->username;
        //if(isset(Yii::app()->user->thisisadmin))
          // unset (Yii::app()->user->thisisadmin);
      }
      else
      {
        $this->errorCode=self::ERROR_PASSWORD_INVALID;
      }
    }
    else
    {
      $this->errorCode=self::ERROR_USERNAME_INVALID;
    }
    unset($user);
    return !$this->errorCode;
  }
  public function getUser()
  {
    return $this->user;
  }
  public function getId()
  {
    return $this->_id;
  }
  public function getUserName()
  {
    return $this->username;
  }
  public function setUser(CActiveRecord $user)
  {
    $this->user=$user->attributes;
  }
}

<?php
/**
 * UserIdentity represents the data needed to identity a user.
 * It contains the authentication method that checks if the provided
 * data can identity the user.
 */
class UserIdentity extends CUserIdentity
{
  /**
   * Authenticates a user.
   * The example implementation makes sure if the username and password
   * are both 'demo'.
   * In practical applications, this should be changed to authenticate
   * against some persistent user identity storage (e.g. database).
   * @return boolean whether authentication succeeds.
   */
  public $admin;
  public $_id;
  public $username;
  public function authenticate()
  {
    $this->errorCode=self::ERROR_PASSWORD_INVALID;
    $user=Staff::model()->find('username=:username',array(':username'=>$this->username));
     if ($user)
    {
      $encrypted_passwd=trim($user->password);
      $inputpassword = trim(md5($this->password));
      if($inputpassword===$encrypted_passwd)
      {
        $this->errorCode=self::ERROR_NONE;
        $this->setUser($user);
        $this->_id=$user->id;
        $this->username=$user->username;
        // Yii::app()->user->setState("thisisadmin", "true");
      }
      else
      {
        $this->errorCode=self::ERROR_PASSWORD_INVALID;
      }
    }
    else
    {
      $this->errorCode=self::ERROR_USERNAME_INVALID;
    }
    unset($user);
    return !$this->errorCode;
  }
  public function getUser()
  {
    return $this->admin;
  }
  public function getId()
  {
    return $this->_id;
  }
  public function getUserName()
  {
    return $this->username;
  }
  public function setUser(CActiveRecord $user)
  {
    $this->admin=$user->attributes;
  }
}