Magento 2.2.0 - __construct() must be an instance of Magento\Framework\View\Result\PageFactory,

Question

Controller File

<?php
namespace Magento2\HelloWorld\Controller\Index;
use \Magento\Framework\App\Action\Action;
use \Magento\Framework\View\Result\PageFactory;
use \Magento\Framework\View\Result\Page;
use \Magento\Framework\App\Action\Context;
use \Magento\Framework\Exception\LocalizedException;
class Index extends Action
{
 /**
 * @var PageFactory
 */
 protected $resultPageFactory;
 /**
 * @param Context $context
 * @param PageFactory $resultPageFactory
 *
 * @codeCoverageIgnore
 * @SuppressWarnings(PHPMD.ExcessiveParameterList)
 */
 public function __construct(
 Context $context,
 PageFactory $resultPageFactory
 ) {
 parent::__construct(
 $context
 );
 $this->resultPageFactory = $resultPageFactory;
 }
 public function execute()
 {
 $resultPage = $this->resultPageFactory->create();
 return $resultPage;
 }
}

It throws below exception while trying to run controller, while I have already mentioned use \Magento\Framework\View\Result\PageFactory;

Fatal error: Uncaught TypeError: Argument 2 passed to Magento2\HelloWorld\Controller\Index\Index::__construct() must be an instance of Magento\Framework\View\Result\PageFactory

If I simply use below, it works

<?php
namespace Magento2\HelloWorld\Controller\Index;
use \Magento\Framework\App\Action\Action;
use \Magento\Framework\View\Result\PageFactory;
use \Magento\Framework\View\Result\Page;
use \Magento\Framework\App\Action\Context;
use \Magento\Framework\Exception\LocalizedException;
class Index extends Action
{
 public function execute()
 {
 $this->_view->loadLayout();
 $this->_view->getLayout()->initMessages();
 $this->_view->renderLayout();
 }
}

How can I resolve the __construct() error ?

• Asad Khan: did you get the solution??? actually I'm facing the same issue

Answer 1

Change __construct function to

public function __construct(
 Context $context,
 PageFactory $resultPageFactory
) {
 $this->resultPageFactory = $resultPageFactory;
 parent::__construct(
 $context
 );
}

and Change

class Index extends \Magento\Framework\App\Action\Action

from

class Index extends Action

Also remove

use \Magento\Framework\App\Action\Action;

• Slimshadddyyy: How come swapping two lines work - ` $this->resultPageFactory = $resultPageFactory; parent::__construct( $context ); ?`

Answer 2

Your code is correct there is no any issue.

Follow below step

1) remove cache: php bin/magento cache:flush

2) remove var/generation : rm -rf var/generation

• Slimshadddyyy: It did not worked.
• Prashant Valanda: Still there is error?
• Slimshadddyyy: No, error is resolved by swapping these two lines in construct function - $this->resultPageFactory = $resultPageFactory; parent::__construct( $context );. Although I tried clearing cache and var/generation, but it did not helped.