magento1为产品gird表格添加缩略图

1、在Girid.php添加：
$this->addColumn('image',array(
    'header'        => Mage::helper('employee')->__('Image'),
    'align'         => 'center',
    'index'         => 'image',/*数据库中存储图片的字段名称*/
    'renderer'      => 'Namespace_ModelName_Block_Adminhtml_Template_Grid_Renderer_Image',
));
2、创建文件Namespace/ModelName/Block/Adminhtml/Template/Grid/Renderer/Image.php
class Namespace_ModelName_Block_Adminhtml_Template_Grid_Renderer_Image extends Mage_Adminhtml_Block_Widget_Grid_Column_Renderer_Abstract
{
    public function render(Varien_Object $row)
    {
        $html  = '<img ';
        $html .= 'id="' . $this->getColumn()->getId() . '" ';
        $html .= 'src="' . $row->getData($this->getColumn()->getIndex()) . '" ';
        $html .= ' width="50" height="40" ';/*自己定义图片宽高*/
        $html .= 'class="grid-image ' . $this->getColumn()->getInlineCss() . '"/>';
        return $html;
    }
}