file upload not working or has some issue in phalconphp

i am new to phalcon and i'm stuck at file uploading in phalcon.

so i googled some basic things but none of those worked , i need someone who can help me to solve this

This is my form | volt file:

<form action="/user/upload" method="post" enctype="multipart/form-data">

    <!-- <input type="file" name="my_picture" >
     --><label>File</label>
    <input type="file" name="upFile" class="form-control">

    <input type="submit" class="btn btn-warning" style="margin-top:15px;" value="Upload">
</form>

This is my controller:

```public function uploadAction() { 
        $this->view->disable();
        if ($this->request->hasFiles() == true) {
            foreach ($this->request->getUploadedFiles() as $file){
                $upload_dir = DIR . '/../../app/public/img/';
                $file->moveTo($upload_dir . $file->getName());
                   echo $file->getName(), '\n';
            }
        } else {
            echo 'File not uploaded';
        }
    } 

When i var_dump($file);

i got this :

002.jpg\nobject(Phalcon\Http\Request\File)#48 (8) { ["_name":protected]=> string(7) "002.jpg" ["_tmp":protected]=> string(0) "" ["_size":protected]=> int(0) ["_type":protected]=> string(0) "" ["_realType":protected]=> NULL ["_error":protected]=> int(3) ["_key":protected]=> string(6) "upFile" ["_extension":protected]=> string(3) "jpg"}