我在学习这门课程https://www.mage-world.com/blog/grid-and-form-in-magento-2-admin-panel-part-1.html但我的 Magento 版本是 2.2.5，所以有点不同。我NewsFactory通过块而不是控制器创建自动，并抛出此错误消息
我在 google 和 stackexchange 上看了 5 个小时，但仍然不知道为什么会出现这个错误。所以这是我的代码：
我的块：C:\xampp\htdocs\magento\app\code\Fudu\HelloWorld\Block\Adminhtml\News.php
<?php
namespace Fudu\HelloWorld\Block\Adminhtml;
use \Magento\Framework\View\Element\Template;
use \Magento\Framework\View\Element\Template\Context;
use \Fudu\HelloWorld\Model\ResourceModel\Students\Collection as StudentsCollection;
use \Fudu\HelloWorld\Model\Students;
use \Fudu\HelloWorld\Model\NewsFactory;
class News extends Template
{
/**
* Constructor
*
*/
/**
* News model factory
* @var null|NewsFactory
*/
protected $_newsFactory = null;
/**
* @param Context $context
* @param NewsFactory $newsFactory
* @param array $data
*/
public function __construct(
Context $context,
NewsFactory $newsFactory,
array $data = []
)
{
$this->_newsFactory = $newsFactory;
parent::__construct($context, $data);
$this->_controller = 'adminhtml_news';
$this->_blockGroup = 'Tutorial_SimpleNews';
$this->_headerText = __('Manage News');
$this->_addButtonLabel = __('Add News');
}
/**
* @return Students[]
*/
/** @var StudentsCollection $studentsCollection */
public function execute()
{
$studentsCollection = $this->_newsFactory->create();
$studentsCollection->addFieldToSelect('*')->load();
return $studentsCollection->getItems();
}
/**
* For a given students, returns its url
* @param Students $students
* @return string
*/
}
我的控制器：C:\xampp\htdocs\magento\app\code\Fudu\HelloWorld\Controller\Adminhtml\News.php
<?php
namespace Fudu\HelloWorld\Controller\Adminhtml;
use Magento\Backend\App\Action;
use Magento\Backend\App\Action\Context;
use Magento\Framework\Registry;
use Magento\Framework\View\Result\PageFactory;
class News extends Action
{
/**
* Core registry
*
* @var \Magento\Framework\Registry
*/
protected $_coreRegistry;
/**
* Result page factory
*
* @var \Magento\Framework\View\Result\PageFactory
*/
protected $_resultPageFactory;
/**
* @param Context $context
* @param Registry $coreRegistry
* @param PageFactory $resultPageFactory
*/
public function __construct(
Context $context,
Registry $coreRegistry,
PageFactory $resultPageFactory
)
{
parent::__construct($context);
$this->_coreRegistry = $coreRegistry;
$this->_resultPageFactory = $resultPageFactory;
}
/**
* News access rights checking
*
* @return bool
*/
public function execute()
{
$resultPage = $this->_resultPageFactory->create();
return $resultPage;
}
}
menu.xml（这是一个来自后端的菜单，当我们点击第三个选项，即“管理新闻”时，它会重定向到 url simplenews/news/index）。C:\xampp\htdocs\magento\app\code\Fudu\HelloWorld\etc\adminhtml\menu.xml
<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="../../../Backend/etc/menu.xsd">
<menu>
<add id="Fudu_HelloWorld::main_menu" title="Simple News"
module="Fudu_HelloWorld" sortOrder="20"
resource="Fudu_HelloWorld::simplenews" />
<add id="Fudu_HelloWorld::add_news" title="Add News"
module="Fudu_HelloWorld" sortOrder="1"
parent="Fudu_HelloWorld::main_menu"
action="simplenews/news/new"
resource="Fudu_HelloWorld::manage_news" />
<add id="Fudu_HelloWorld::manage_news" title="Manage News"
module="Fudu_HelloWorld" sortOrder="2"
parent="Fudu_HelloWorld::main_menu"
action="simplenews/news/index"
resource="Fudu_HelloWorld::manage_news" />
<add id="Fudu_HelloWorld::configuration" title="Configurations"
module="Fudu_HelloWorld" sortOrder="3"
parent="Fudu_HelloWorld::main_menu"
action="adminhtml/system_config/edit/section/simplenews"
resource="Fudu_HelloWorld::configuration" />
</menu>
</config>
我的观点：C:\xampp\htdocs\magento\app\code\Fudu\HelloWorld\view\adminhtml\layout\simplenews_news_index.xml
<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="../../../../../../../lib/internal/Magento/
Framework/View/Layout/etc/page_configuration.xsd">
<update handle="formkey"/>
<update handle="simplenews_news_grid_block"/>
<body>
<referenceContainer name="content">
<block class="Fudu\HelloWorld\Block\Adminhtml\News"
name="tutorial_simplenews_news.grid.container" />
</referenceContainer>
</body>
</page>
感谢您阅读本文，祝您有美好的一天。