【原创】GridView使用kartik扩展yii2-export导出ExportMenu文档前后加内容

今天yii2表格GridView使用kartik扩展yii2-export导出excel文档的时候需要在表格内容前面或后面加一些说明内容，结果官方文档说明也不是很清楚，查看vendor\kartik-v\yii2-export\src\ExportMenu.php源码发现有contentBefore和contentAfter两个属性可以用，尝试下果然可以，代码如下：

<?php echo  ExportMenu::widget([
   'dataProvider' => $dataProvider,
   'columns' => $columns,
   'showColumnSelector' => false,
   'asDropdown' => false,
   'exportConfig' => [
      ExportMenu::FORMAT_HTML => false,
      ExportMenu::FORMAT_CSV => false,
      ExportMenu::FORMAT_TEXT => false,
      ExportMenu::FORMAT_PDF => false,
      ExportMenu::FORMAT_EXCEL => false,
      ExportMenu::FORMAT_EXCEL_X => [
         'icon' => '',
         'iconOptions' => ['class' => ''],
         'label' => '<button id="download">导出</button>',
         'options' => ['class' => 'btn btn-primary', 'style' => 'display:none'],
      ],
   ],
   //导出excel内容前面加内容
   'contentBefore' => [
      ['value' => 'v1'],
      ['value' => 'v2'],
   ],
   //导出excel内容后面加内容
   'contentAfter' => [
      ['value' => 'v1'],
      ['value' => 'v2'],
   ],
   'filename' => date('YmdHi'),
]);

导出如图：