I was tried many ways finally its worked thanks man.
<?php
namespace vendor\module\Observer;
class ProductSaveAfter implements \Magento\Framework\Event\ObserverInterface
{
public function __construct(
\Magento\Backend\Model\Auth\Session $authSession,
\Magento\Catalog\Model\ProductFactory $productFactory
) {
$this->authSession = $authSession;
$this->productFactroy = $productFactory;
}
public function execute(\Magento\Framework\Event\Observer $observer)
{
$user = $this->authSession->getUser()->getUsername();
$productId = (int) $observer->getProduct()->getId();
$product = $this->productFactroy->create()->load($productId);
$product->addAttributeUpdate("updated_by", $user, 0);//attribute,value,storeid
}
}
To Update the custom attribute value please follow the below code, it could be help you...
$objectManager = \Magento\Framework\App\ObjectManager::getInstance();
$productRepository = $objectManager->create('\Magento\Catalog\Api\ProductRepositoryInterface');
$product = $productRepository->getById($productId);
$product->addAttributeUpdate($attributeCode, $attributeValue, $storeId);
$productRepository->save($product);Thanks.