DI not working in Controller

Question

I have a Controller that contains the following:

...

use Magento\Backend\App\Action;
use Magento\TestFramework\ErrorLog\Logger;
use Magento\MediaStorage\Model\File\UploaderFactory;
use MyNamespace\Slider\Model\SliderImage;

class Save extends \Magento\Backend\App\Action
{

    /** @var UploaderFactory */
    protected $uploaderFactory;

    /** @var SliderImage */
    protected $imageModel;

    public function __construct(
        Action\Context $context,
        UploaderFactory $uploaderFactory,
        SliderImage $imageModel
    )
    {
        parent::__construct($context);
        $this->uploaderFactory = $uploaderFactory;
        $this->imageModel = $imageModel;
    } 

    ...
}

I am using this to save a form in the admin. It was working properly without the UploaderFactory and SliderImage in the __contruct.

I am now trying to add an Image field to the form. I have added the dependencies, UploaderFactory and SliderImage and now get the error:

Uncaught TypeError: Argument 2 passed to MyNamespace\Slider\Controller\Adminhtml\Image\Save::__construct() must be an instance of Magento\MediaStorage\Model\File\UploaderFactory, none given, called in /var/www/html/generated/code/MyNamespace/Slider/Controller/Adminhtml/Image/Save/Interceptor.php on line 14 and defined in /var/www/html/app/code/MyNamespace/Slider/Controller/Adminhtml/Image/Save.php:19 Stack trace: #0 /var/www/html/generated/code/MyNamespace/Slider/Controller/Adminhtml/Image/Save/Interceptor.php(14): MyNamespace\Slider\Controller\Adminhtml\Image\Save->__construct(Object(Magento\Backend\App\Action\Context)) #1 /var/www/html/lib/internal/Magento/Framework/ObjectManager/Factory/AbstractFactory.php(111): MyNamespace\Slider\Controller\Adminhtml\Image\Save\Interceptor->__construct(Object(Magento\Backend\App\Action\Context)) #2 /var/www/html/lib/internal/Magento/Framework/ObjectManager/Factory/Dynamic/Developer.php(66): Magento\Framework\ObjectManager\Factory\AbstractFactory->createObject('MyNamespace\Slider...', Array)

Answer 1

If you are using Magento 2.1.9 or less than clear var/generation, var/cache directory and if you are 2.2.0 or greater than remove generated/code and generated/metadata folder.

Thanks

Answer 2

Clear var/generation folder and refresh, the error will be gone.