Magento – Magento:2 How tomage upload in custom module

You need to change in style.less or style.css in your theme folder and then deploy content as follows.

php bin/magento setup:static-content:deploy

You need to run above command from Magento 2 root directory.

in controller

namespace Abc\Xyz\Controller\Adminhtml\Index;

 use Exception;
use \Magento\Backend\App\Action;
use Magento\Framework\App\Filesystem\DirectoryList;
use Magento\Framework\App\ResponseInterface;
use Magento\Framework\Controller\Result\Redirect;
use Magento\Framework\Controller\ResultInterface;
use Magento\Framework\Filesystem;
use Magento\Framework\UrlInterface;
use Magento\MediaStorage\Model\File\UploaderFactory;
use Abc\Xyz\Model\GuestOffers;
use Magento\Framework\App\Request\DataPersistorInterface;
use Magento\Framework\Exception\LocalizedException;
use Magento\Store\Model\StoreManagerInterface;

class Save extends Action
{
protected $dataProcessor;
protected $dataPersistor;
protected $imageUploader;
protected $model;
/**
 * @var Filesystem
 */
private $_filesystem;

public function __construct(
    Action\Context $context,
    PostDataProcessor $dataProcessor,
    DataPersistorInterface $dataPersistor,
    StoreManagerInterface $storeManager,
    Filesystem $filesystem,
    UploaderFactory $fileUploaderFactory,
    GuestOffers $model

) {
    $this->dataProcessor = $dataProcessor;
    $this->dataPersistor = $dataPersistor;
    $this->_storeManager = $storeManager;
    $this->_filesystem = $filesystem;
    $this->_fileUploaderFactory = $fileUploaderFactory;
    $this->model = $model;
    parent::__construct($context);
}

/**
 * @return ResponseInterface|Redirect|ResultInterface
 */
public function execute()
{
    $resultRedirect = $this->resultRedirectFactory->create();

    $data = $this->getRequest()->getPostValue();

    $files = $this->getRequest()->getFiles(); // we can not get images through $_FILES Global Variable. So Instead we will use this.

    $mediaDir = $this->_filesystem->getDirectoryRead(DirectoryList::MEDIA)->getAbsolutePath();
    $mediapath = $this->_mediaBaseDirectory = rtrim($mediaDir, '/');

    //check if we got some images or not
    if (isset($files['var_banner']) && !empty($files['var_banner']['name'])) {
        try {
            $uploader = $this->_fileUploaderFactory->create(['fileId' => 'var_banner']);
            $uploader->setAllowedExtensions(['jpg', 'jpeg', 'gif', 'png']);
            $uploader->setAllowRenameFiles(true);

            $path = $mediapath . '/guest_offers/';  //folder name where images will be moved.

            $data['var_banner'] = str_replace(' ', '_', $files['var_banner']['name']);  //remove space form iamge name and add UNDERSCORE (_).

            $result = $uploader->save($path); //save complete path of image.
        } catch (\Exception $e) {
            $data['var_banner'] = ''; // if image is not uploaded successfully. Save it as null.
            $this->messageManager->addError(__('an error occured while saving image.'));
        }
    }

    $data = $this->dataProcessor->filter($data); //get all other fields posted data.

    $id = $this->getRequest()->getParam('id');
    if ($id) {
        $this->model->load($id);
    }
    $this->model->setData($data);
    $this->_eventManager->dispatch(
        'guestoffers_prepare_save',
        ['sales' => $this->model, 'request' => $this->getRequest()]
    );

    if (!$this->dataProcessor->validate($data)) {
        return $resultRedirect->setPath('*/*/edit', ['id' => $this->model->getId(), '_current' => true]);
    }
    try {
        $this->model->save();
        $this->messageManager->addSuccessMessage(__('You saved the New Guest Offer.'));
        $this->dataPersistor->clear('gestoffers');
        if ($this->getRequest()->getParam('back')) {
            return $resultRedirect->setPath(
                '*/*/edit',
                ['id' => $this->model->getId(),
                    '_current' => true]
            );
        }
        return $resultRedirect->setPath('*/*/edit');
    } catch (LocalizedException $e) {
        $this->messageManager->addErrorMessage($e->getMessage());
    } catch (Exception $e) {
        $this->messageManager->addExceptionMessage($e, __('Something went wrong while saving new offer.'));
    }

    $this->dataPersistor->set('guestoffers', $data);
    return $resultRedirect->setPath('*/*/edit', ['id' => $this->getRequest()->getParam('id')]);
}
}