上传图像Yii时出错

上传图像时遇到问题。错误提示：include（CUploadFile.php）：无法打开流：没有这样的文件或目录。

我的数据库中有一个表，tbl_barang（id_barang、nama_barang、id_merk、harga、foto、deskripsi）

这是我的型号，Barang.php

<?php
    class Barang extends CActiveRecord {
    public static function model($className=__CLASS__) {
        return parent::model($className);
    }
    public function tableName() {
        return 'tbl_barang';
    }
    public function rules() {
        return array(
            array('nama_barang, id_merk, harga, foto, deskripsi', 'required'),
            array('harga', 'numerical', 'integerOnly'=>true),
            array('nama_barang', 'length', 'max'=>50),
            array('id_merk', 'length', 'max'=>3),
            array('foto', 'file', 'types'=>'jpg, gif, png', 'allowEmpty'=>true,), //menentukan file, tipe file, dan boleh empty pada validasi upload foto
            array('id_barang, nama_barang, id_merk, harga, foto, deskripsi', 'safe', 'on'=>'search'),
        );
    }
    public function relations() {
        return array();
    }
    public function attributeLabels() {
        return array(
            'id_barang' => 'Id Barang',
            'nama_barang' => 'Nama Barang',
            'id_merk' => 'Id Merk',
            'harga' => 'Harga',
            'foto' => 'Foto',
            'deskripsi' => 'Deskripsi',
        );
    }
    public function search() {
        $criteria=new CDbCriteria;
        $criteria->compare('id_barang',$this->id_barang);
        $criteria->compare('nama_barang',$this->nama_barang,true);
        $criteria->compare('id_merk',$this->id_merk,true);
        $criteria->compare('harga',$this->harga);
        $criteria->compare('foto',$this->foto,true);
        $criteria->compare('deskripsi',$this->deskripsi,true);
        return new CActiveDataProvider($this, array(
            'criteria'=>$criteria,
        ));
    }
}

然后是我的控制器BarangController.php

class BarangController 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'.
     */
    //menentukan layout
    public $layout='//layouts/column2';
    //menentukan folder tempat penyimpanan
    const URLUPLOAD='/../images/barang';
    /**
     * @return array action filters
     */
    public function filters() {
        return array(
            'accessControl', // perform access control for CRUD operations
            'postOnly + delete', // we only allow deletion via POST request
        );
    }
    /**
     * Specifies the access control rules.
     * This method is used by the 'accessControl' filter.
     * @return array access control rules
     */
    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('*'),
            ),
        );
    }
    /**
     * Displays a particular model.
     * @param integer $id the ID of the model to be displayed
     */
    public function actionView($id) {
        $this->render('view',array(
            'model'=>$this->loadModel($id),
        ));
    }
    /**
     * Creates a new model.
     * If creation is successful, the browser will be redirected to the 'view' page.
     */
    public function actionCreate() {
        $model=new Barang; //panggil model Barang
        // Uncomment the following line if AJAX validation is needed
        // $this->performAjaxValidation($model);
        if(isset($_POST['Barang'])) { //jika data dikirim
            //cek file
            $cekfile = $model->image=CUploadFile::getInstance($model, 'foto');
            if(empty($cekfile)) { //jika file kosong
                //ambil data yang diinput
                $model->attributes=$_POST['Barang'];
                $model->save();
            } else { //jika file tidak kosong
                //ambil data yang diinput
                $model->attributes=$_POST['Barang'];
                //ambil file
                $model->image = CUploadFile::getInstance($model, 'foto');
                if($model->save()) { //jika data disimpan
                    //upload image ke folder
                    $model->image->saveAs(Yii::app()->basePath.self::URLUPLOAD.$model->image.'');
                    //alihkan ke halaman index/function actionIndex()
                    $this->redirect(array('view','id'=>$model->id_barang));
                }
            }
        }
        $this->render('create',array(
            'model'=>$model,
        ));
    }
    /**
     * Updates a particular model.
     * If update is successful, the browser will be redirected to the 'view' page.
     * @param integer $id the ID of the model to be updated
     */
    public function actionUpdate($id) {
        $model=$this->loadModel($id);
        // Uncomment the following line if AJAX validation is needed
        // $this->performAjaxValidation($model);
        if(isset($_POST['Barang'])) {
            $model->attributes=$_POST['Barang'];
            if($model->save())
                $this->redirect(array('view','id'=>$model->id_barang));
        }
        $this->render('update',array(
            'model'=>$model,
        ));
    }
    /**
     * Deletes a particular model.
     * If deletion is successful, the browser will be redirected to the 'admin' page.
     * @param integer $id the ID of the model to be deleted
     */
    public function actionDelete($id) {
        $this->loadModel($id)->delete();
        // if AJAX request (triggered by deletion via admin grid view), we should not redirect the browser
        if(!isset($_GET['ajax']))
            $this->redirect(isset($_POST['returnUrl']) ? $_POST['returnUrl'] : array('admin'));
    }
    /**
     * Lists all models.
     */
    public function actionIndex() {
        $dataProvider=new CActiveDataProvider('Barang');
        $this->render('index',array(
            'dataProvider'=>$dataProvider,
        ));
    }
    /**
     * Manages all models.
     */
    public function actionAdmin() {
        $model=new Barang('search');
        $model->unsetAttributes();  // clear any default values
        if(isset($_GET['Barang']))
            $model->attributes=$_GET['Barang'];
        $this->render('admin',array(
            'model'=>$model,
        ));
    }
    /**
     * Returns the data model based on the primary key given in the GET variable.
     * If the data model is not found, an HTTP exception will be raised.
     * @param integer the ID of the model to be loaded
     */
    public function loadModel($id) {
        $model=Barang::model()->findByPk($id);
        if($model===null)
            throw new CHttpException(404,'The requested page does not exist.');
        return $model;
    }
    /**
     * Performs the AJAX validation.
     * @param CModel the model to be validated
     */
    protected function performAjaxValidation($model) {
        if(isset($_POST['ajax']) && $_POST['ajax']==='barang-form') {
            echo CActiveForm::validate($model);
            Yii::app()->end();
        }
    }
}

在_form.php中，我只是将foto行中的textfiled更改为filefield。我真的很困惑为什么它不能上传。我希望任何人都能帮助我，教我如何修复它。谢谢