โค๊ดผมเรียก fn ภายใต้คลาสเดียวกันทำไมใช้ $this-> ไม่ได้ต้องใช้ชื่อคลาสแทน

<?php
class RTypeController extends Controller
{
	/**
	 * @var string the default layout for the views. Defaults to '//layouts/column2', meaning
	 * using two-column layout. See 'protected/views/layouts/column2.php'.
	 */
	public $layout='//layouts/column2';

    /* ImageLink open Popup FancyBox */
    public static function imgFancy($targetID,$path){
        if($path!=''){
            //  ทำไมใช้ $this-> แทน RTypeController:: ไม่ได้
            $link = RTypeController::fancyLink_img($targetID, $path);
            $link .= RTypeController::fancyContent_img($targetID, $path);
        }else $link='no image';
        return $link;
    }
    /* Link open FancyBox */
    public static function fancyLink_img($targetID,$path){
        if($path!=''){
            $image = CHtml::image($path,NULL,array("class"=>"fancy-thumb"));
            $link = CHtml::link($image, '#'.$targetID,array("class"=>"fancy-click"));
        }else $link='no image';
        return $link;
    }
    /* Content in FancyBox */
    public static function fancyContent_img($targetID,$path){
        if($path!=''){
            $image = CHtml::image($path,NULL,array('id'=>$targetID,"class"=>"fancy-content"));
        }else $image='no image';
        return $image;
    }

    public function render_RTypeNum($data,$row){
        // Find the number of "RTypeID" RDetail:
        // SELECT COUNT(*) FROM h_rdetail WHERE RTypeID= $data->RTypeID
        $criteria = new CDbCriteria();
        $criteria->condition = 'RTypeID='.$data->RTypeID;
        $count = RDetail::model()->count($criteria);

        return $data->RTypeName." ($count) ";
    }

	public function filters()
	{
		return array(
			'accessControl', // perform access control for CRUD operations
			'postOnly + delete', // we only allow deletion via POST request
		);
	}

	public function accessRules()
	{
		return array(
			array('allow',  // allow all users to perform 'index' and 'view' actions
				'actions'=>array('index','view'),
				'users'=>array('*'),
			),
			array('allow', // allow authenticated user to perform 'create' and 'update' actions
				'actions'=>array('create','update'),
				'users'=>array('@'),
			),
			array('allow', // allow admin user to perform 'admin' and 'delete' actions
				'actions'=>array('admin','delete'),
				'users'=>array('admin'),
			),
			array('deny',  // deny all users
				'users'=>array('*'),
			),
		);
	}

	public function actionView($id)
	{
		$this->render('view',array(
			'model'=>$this->loadModel($id),
		));
	}


	/**
	 * Lists all models.
	 */
	public function actionIndex()
	{
		$dataProvider=new CActiveDataProvider('RType');
		$this->render('index',array(
			'dataProvider'=>$dataProvider,
		));
	}

	/**
	 * Manages all models.
	 */
	public function actionAdmin()
	{
		$model=new RType('search');
		$model->unsetAttributes();  // clear any default values
		if(isset($_GET['RType']))
			$model->attributes=$_GET['RType'];
        
		$this->render('admin',array(
			'model'=>$model,
		));
	}

	public function loadModel($id)
	{
		$model=RType::model()->findByPk($id);
		if($model===null)
			throw new CHttpException(404,'The requested page does not exist.');
		return $model;
	}

	protected function performAjaxValidation($model)
	{
		if(isset($_POST['ajax']) && $_POST['ajax']==='rtype-form')
		{
			echo CActiveForm::validate($model);
			Yii::app()->end();
		}
	}
}

$this->widget('zii.widgets.grid.CGridView', array(
	'id'=>'rtype-grid',
	'dataProvider'=>$model->search(),
	'filter'=>$model,
//    'afterAjaxUpdate'=>'function(){fancy();}',
	'columns'=>array(
        array(
			'name'=>'RTypeID',
            'htmlOptions'=>array('width'=>'20px', 'style'=>'text-align:center'),
		),
        array(
			'name'=>'RTypeName',
            'type'=>'raw',
            'header'=>RType::model()->attributeLabels()['RTypeName'].' (จำนวนห้อง)',
            'value'=>array($this,'render_RTypeNum'),
		),
        array(
			'name'=>'RTypeDetail',
            'type'=>'raw',
            'htmlOptions'=>array('width'=>'300px'),
		),
        array(
			'name'=>'Rcustnum',
            'htmlOptions'=>array('width'=>'30px', 'style'=>'text-align:center'),
		),
        array(
			'name'=>'RPictures',
            'type'=>'raw',
            'value'=>'$this->imgFancy("fancy".$row,$data->RPictures)',
            'htmlOptions'=>array('width'=>'70px', 'style'=>'text-align:center'),
		),
		array(
			'name'=>'PriceDefault',
            'htmlOptions'=>array('width'=>'70px', 'style'=>'text-align:right'),
		),
	array(
			'class'=>'CButtonColumn',
            'header'=>CHtml::link('Reset', array('')),
		),
	),
)); 

//เช่นกันใช้ $this ไม่ได้
'value'=>'$this->imgFancy("fancy".$row,$data->RPictures)',
//ต้องเรียกแบบนี้
'value'=>'RTypeController::imgFancy("fancy".$row,$data->RPictures)',
//แต่ถ้าเรียกแบบนี้ได้ 
'value'=>array($this,'imgFancy'),