优化图片加载已修复fixed表现；优化导出功能，使导出效果与页面表格一致；

app/admin/controller/mall/Goods.php

@@ -9,7 +9,11 @@ use app\admin\traits\Curd;
 use app\common\controller\AdminController;
 use EasyAdmin\annotation\ControllerAnnotation;
 use EasyAdmin\annotation\NodeAnotation;
+use PhpOffice\PhpSpreadsheet\Cell\Coordinate;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx;
 use think\App;
+use think\helper\Arr;
 
 /**
  * Class Goods
@@ -83,5 +87,5 @@ class Goods extends AdminController
         $this->assign('row', $row);
         return $this->fetch();
     }
-
-}
+    
+}