文章编辑页面用户可以不上传图片，就是用原来的图片，可是会提示一定要上传图片 [ 1.1 版本 ]

model

public function rules()
{
    return array(
        array('title', 'required','message'=>'标题必填'),
        array('cid', 'check_cid'),
        array('type', 'in','range'=>array(0,1),'message'=>'请选择类型'),
        array('info', 'required','message'=>'摘要必填'),
        array('thumb','file','types'=>'jpg,gif,png,jpeg,bmp', 'wrongType'=>'类型不符','wrongMimeType'=>'类型不符','message'=>'没有上传'),
        array('content', 'required','message'=>'内容必填'),
    );
}

控制器add

public function actionAdd()
{
    $articleModel = new Article();
    $categoryModel = category::model();
    $categoryList =  $categoryModel-> findAll();
    $list=array();
    $list[]='请选择栏目';
    foreach ($categoryList as $cat) {
        $list[$cat->cid]=$cat->cname;
    }
    if(isset($_POST['Article'])){
        $articleModel->attributes=$_POST['Article'];
        $img = CUploadedFile::getInstance($articleModel, 'thumb');
        if(is_object($img) && $img instanceof CUploadedFile){
            $pre='img_'.time().mt_rand(10000, 99999);
            $ext=$img->extensionName;
            $articleModel->thumb=$pre.'.'.$ext;				
        }else{
            $articleModel->thumb='no.jpg';
        }
        $articleModel->time=time();
        if($articleModel->save()){
            if(is_object($img) && $img instanceof CUploadedFile){
                $img->saveAs('uploads/' . $pre.'.'.$ext);
            }
            Yii::app()->user->setFlash('success','添加成功');
            $this->redirect(array('index'));
        }else{
            Yii::app()->user->setFlash('success','添加失败');
        }				
        
    }
    $this->render('add',array('articleModel'=>$articleModel,'list'=>$list));
}

控制器update

public function actionEdit($aid)
{
    $articleModel = Article::model();
    $articleinfo = $articleModel->findByPk($aid);		
    $categoryModel = category::model();
    $categoryList =  $categoryModel-> findAll();
    $list=array();
    $list[]='请选择栏目';
    foreach ($categoryList as $cat) {
        $list[$cat->cid]=$cat->cname;
    }		
    if(isset($_POST['Article'])){
        $origimg = $articleinfo->thumb;
        $articleinfo->attributes=$_POST['Article'];
        $img = CUploadedFile::getInstance($articleModel, 'thumb');
        if(is_object($img) && $img instanceof CUploadedFile){
            $pre='img_'.time().mt_rand(10000, 99999);
            $ext=$img->extensionName;
            $articleinfo->thumb=$pre.'.'.$ext;				
        }else{
            $articleinfo->thumb=$origimg;
        }
        $articleinfo->time=time();
        if($articleinfo->save()){
            if(is_object($img) && $img instanceof CUploadedFile){
                $img->saveAs('uploads/' . $pre.'.'.$ext);
            }
            Yii::app()->user->setFlash('success','编辑成功');
            $this->redirect(array('index'));
        }else{
            Yii::app()->user->setFlash('success','编辑失败');
        }				
        
    }
    $this->render('edit',array('articleinfo'=>$articleinfo,'list'=>$list));
}