我试图使我的列表视图的项目在我的底部工作表滚动。我使它与DraggableScrollableSheet小部件，但有这个尴尬白色。有人能检查我的代码，并告诉我什么是错的？

onPressed: () {
    showModalBottomSheet(
      isDismissible: true,
      isScrollControlled: true,
      context: context,
      shape: const RoundedRectangleBorder(
          borderRadius: const BorderRadius.vertical(
        top: Radius.circular(20),
      )),
      builder: (context) => DraggableScrollableSheet(
initialChildSize: 0.7,
minChildSize: 0.2,
maxChildSize: 0.75,
builder: (_, controller) => Container(
        padding: const EdgeInsets.all(16),
        child: ListView(
          children: [
            Image.network(
              imageURl,
              loadingBuilder: (context, child, loadingProgress) {
                if (loadingProgress == null) return child;
                return const CircularProgressIndicator();
              },
              errorBuilder: (context, error, stackTrace) =>
                  Text(errorMessage),
            ),
            ListTile(
              title: Text(
                information1,
                textAlign: TextAlign.justify,
              ),
            ),
            ListTile(
              title: Text(
                information2,
                textAlign: TextAlign.justify,
              ),
            ),
            Padding(
              padding: const EdgeInsets.all(10.0),
              child: Container(
                child: CupertinoButton.filled(
                  padding: EdgeInsets.all(15),
                  child: Text(information3),
                  onPressed: () async {
                    if (await canLaunch(linkURl)) {
                      await launch(
                        linkURl,
                        universalLinksOnly: true,
                      );
                    } else {
                      throw 'There was a problem to open the url.';
                    }
                  },
                ),
              ),
            ),
          ],
        ),
      ),
    ),
    );
  },

工作原理示例：

正如你在上面的视频中所看到的，在图片的顶部有一个令人尴尬的白色。是什么原因造成的？我该如何消除它？
谢谢！