在magento admin中添加多个网格

Question

我现在创建了一个成功显示数据的网格，现在我想创建另一个网格我的文件和代码结构如下

包含网格数据代码的网格类

<?php
class Shop_Shop_Block_Adminhtml_Shop_Grid extends Mage_Adminhtml_Block_Widget_Grid
{
    public function __construct()
    {
        parent::__construct();
        $this->setId('shopGrid');
        $this->setDefaultSort('id');
        $this->setDefaultDir('DESC');
        $this->setSaveParametersInSession(true);
        $this->setUseAjax(true);
    }

    protected function _prepareCollection()
    {
        $collection = Mage::getResourceModel('catalog/product_collection');
        $collection->addAttributeToSelect('*');
        $collection->joinTable('catalog/category_product', 'product_id=entity_id', array(
            'my_cat' => 'category_id'
        ), null, 'left');
        $collection->joinTable('catalog_category_entity_varchar', 'entity_id=my_cat', array(
            'mv' => 'value'
        ), null, 'left');
        $collection->groupByAttribute('entity_id');
        $this->setCollection($collection);
        return parent::_prepareCollection();
    }

    protected function _prepareColumns()
    {
        $this->addColumn('id', array(
            'header' => 'Product ID',
            'align' => 'left',
            'width' => '10',
            'index' => 'entity_id'
        ));
        $this->addColumn('name', array(
            'header' => 'Name',
            'align' => 'left',
            'index' => 'name'
        ));
        $this->addColumn('price', array(
            'header' => 'Price',
            'align' => 'left',
            'class' => 'myid',
            'index' => 'price'
        ));
        $this->addColumn('category', array(
            'header' => 'Category',
            'align' => 'left',
            'index' => 'mv'
        ));
        $this->addColumn('edit', array(
            'header' => Mage::helper('catalog')->__('Action'),
            'width' => '50px',
            'type' => 'action',
            'getter' => 'getId',
            'actions' => array(
                array(
                    'caption' => Mage::helper('catalog')->__('Edit'),
                    'url' => array(
                        'base' => '../../admin/catalog_product/edit'
                    ),
                    'field' => 'id'
                )
            ),
            'filter' => false,
            'sortable' => false,
            'index' => 'stores'
        ));
        $this->addColumn('delete', array(
            'header' => Mage::helper('catalog')->__('Action'),
            'width' => '50px',
            'type' => 'action',
            'getter' => 'getId',
            'actions' => array(
                array(
                    'caption' => Mage::helper('catalog')->__('Delete'),
                    'url' => array(
                        'base' => '*/*/../../admin/catalog_product/delete'
                    ),
                    'field' => 'id'
                )
            ),
            'filter' => false,
            'sortable' => false,
            'index' => 'stores'
        ));
        return parent::_prepareColumns();
    }
}
?>        
<?php
class Shop_Shop_Block_Adminhtml_Shop extends Mage_Adminhtml_Block_Widget_Grid_Container
{
    public function __construct()
    {
        $this->_controller = 'adminhtml_shop';
        $this->_blockGroup = 'shop';
        $this->_headerText = 'My product';
    }
}
?>    

我的商店xml，用于显示我的模板和网格

<?xml version="1.0" encoding="UTF-8"?>
<layout version="1.0.1">
    <shop_index_index>
        <reference name="content">
            <block name="shop_index" type="page/html" template="shop/index.phtml" />
        </reference>
        <reference name="head">
            <action method="addJs">
                <script>shop/jquery-2.1.4.min.js</script>
            </action>
            <action method="addCss">
                <stylesheet>shop/shop-admin.css</stylesheet>
            </action>
            <action method="addJs">
                <script>shop/shop-admin.js</script>
            </action>
        </reference>
    </shop_index_index>
    <shop_index_main>
        <reference name="content">
            <block name="shop_main" type="page/html" template="shop/main.phtml" />
            <block name="shop_grid" type="shop/adminhtml_grid" />
        </reference>
        <reference name="head">
            <action method="addJs">
                <script>shop/jquery-2.1.4.min.js</script>
            </action>
            <action method="addCss">
                <stylesheet>shop/shop-admin.css</stylesheet>
            </action>
            <action method="addJs">
                <script>shop/shop-admin.js</script>
            </action>
        </reference>
    </shop_index_main>
</layout>

我已经成功创建了一个网格，但现在我想创建另一个网格。请帮助并提供此问题的任何解决方案