如何在YII中允许使用特殊字符上传文件名？

Question

我想上传名称中包含特殊字符的文件（如@，＃，！，〜等）。如何允许带有这些字符的文件名。我的代码是：

public function actionAddImage()
{           

    $model=new Gallery;
    $this->pageTitle = CHtml::encode(Yii::app()->name).' :: Add Image';

    if(isset($_POST['Gallery']))
    {
        $rnd = rand(0,9999);
        $model->attributes=$_POST['Gallery'];
        $uploadedFile = CUploadedFile::getInstance($model,'image');

        $fileName = "{$rnd}-{$uploadedFile}";

        $model->image = $fileName;
        $model->description = $_POST['Gallery']['description'];

        if($model->save())
        {               
             $uploadedFile->saveAs(Yii::getPathOfAlias('webroot').'/upload/'.$fileName); // image will uplode to rootDirectory/banner/

             //thumbmail---------------start---
            Yii::app()->thumb->setThumbsDirectory('/upload/original/');             
            Yii::app()->thumb->load(Yii::getPathOfAlias('webroot').'/upload/'.$fileName)->resize(538,359)->save($fileName);

            Yii::app()->thumb->setThumbsDirectory('/upload/thumb/');                
            Yii::app()->thumb->load(Yii::getPathOfAlias('webroot').'/upload/'.$fileName)->resize('0','110')->save($fileName);   

            Yii::app()->thumb->setThumbsDirectory('/upload/thumb_70/');
            Yii::app()->thumb->load(Yii::getPathOfAlias('webroot').'/upload/'.$fileName)->resize('0',70)->save($fileName);  

            Yii::app()->user->setFlash('employee','Image has been added successfully');
            $this->redirect(array('ManageGalleries'));
        }
    }
    $this->layout = "loginMain";
    $this->render('create',array(
        'model'=>$model,
    ));
}

当我尝试上传包含特殊字符的文件时，不上传文件。 请帮助我如何允许这个文件名。