问删除颤动警报对话框的灰色背景

EN

CupertinoDialogAction(
        child: Text('Delete',
                style: TextStyle(color: Colors.red),
              ),
              onPressed: () async {
                await CommentActivity.delete(postData[index]['id'])
                  .then((response) {
                  if (response) {
                    setState(() {
                      postData.removeAt(index);
                      createPageActivity();
                      renderPageActivity();
                    });
                    Navigator.of(context).pop();
                  }
                });
              }
            )
          ],
        )