/**
 * file
 *
 * @var TYPO3CMSExtbaseDomainModelFileReference
 */
protected $file = null;
/**
 * Returns the file
 *
 * @return TYPO3CMSExtbaseDomainModelFileReference $file
 */
public function getFile()
{
    return $this->file;
}

/**
 * Sets the file
 *
 * @param TYPO3CMSExtbaseDomainModelFileReference $file
 * @return void
 */
public function setFile(TYPO3CMSExtbaseDomainModelFileReference $file)
{
    $this->file = $file;
}

<f:form.upload  property="file" />

/**
*action initialise
*
*@return void
*/
public function initializeAction() {
    $this->controllerContext = $this->buildControllerContext();
    $arg = $this->request->hasArgument('newFile') ? 'newFile' : 'file';
    if (isset($this->arguments[$arg])) {
$uploadConfiguration = array(
            UploadedFileReferenceConverter::CONFIGURATION_ALLOWED_FILE_EXTENSIONS => 'jpg,jpeg,html,css,html,png,bmp,txt,doc,docx,xlf,ico,gif,ogg,tiff',
            UploadedFileReferenceConverter::CONFIGURATION_UPLOAD_FOLDER => 'uploads/tx_pitsbannermanagement',
        );
        /** @var PropertyMappingConfiguration $newFileConfiguration */
        $newFileConfiguration = $this->arguments[$arg]->getPropertyMappingConfiguration();
        $newFileConfiguration->forProperty('file')->setTypeConverterOptions('vendor\Extension\Property\Typeconverter\UploadedFileReferenceConverter',$uploadConfiguration);

    }
}