Flutter : Image.memory widget unable to load

Question

We are trying to create custom gallery page, so that we have followed some tutorial website but facing some issue unable to compile the project.

Tutorial link ::

https://medium.com/@mhstoller.it/how-to-create-a-custom-media-picker-in-flutter-to-select-photos-and-videos-from-the-gallery-988eea477643

class MediaGrid extends StatefulWidget {
  @override
  _MediaGridState createState() => _MediaGridState();
}
class _MediaGridState extends State<MediaGrid> {
  List<Widget> _mediaList = [];
  int currentPage = 0;
  late int lastPage;
  @override
  void initState() {
    super.initState();
    _fetchNewMedia();
  }
  _handleScrollEvent(ScrollNotification scroll) {
    if (scroll.metrics.pixels / scroll.metrics.maxScrollExtent > 0.33) {
      if (currentPage != lastPage) {
        _fetchNewMedia();
      }
    }
  }
  Future<ui.Image> loadImage(Uint8List img) async {
    final Completer<ui.Image> completer = Completer();
    ui.decodeImageFromList(img, (ui.Image img) {
      return completer.complete(img);
    });
    return completer.future;
  }
  static Future<ui.Image> bytesToImage(Uint8List imgBytes) async{
    ui.Codec codec = await ui.instantiateImageCodec(imgBytes);
    ui.FrameInfo frame = await codec.getNextFrame();
    return frame.image;
  }

  _fetchNewMedia() async {
    lastPage = currentPage;

    final PermissionState _ps = await PhotoManager.requestPermissionExtend();
    if (_ps.isAuth) {
      // success
//load the album list
      List<AssetPathEntity> albums =
      await PhotoManager.getAssetPathList(onlyAll: true);
      print(albums);
      List<AssetEntity> media =
      await albums[0].getAssetListPaged(page: currentPage, size: 60);
      // await albums[0].getAssetListPaged(currentPage, 60);
      List<Widget> temp = [];
      for (var asset in media) {
        temp.add(
          FutureBuilder(
            future: asset.thumbnailDataWithSize(const ThumbnailSize(200, 200)),
            builder: (BuildContext context, snapshot) {
              if (snapshot.connectionState == ConnectionState.done) {
                return Stack(
                  children: [
                    // Image.asset(
                    //   "assets/images/gallery.png",
                    //   fit: BoxFit.cover,
                    // ),
                    Positioned.fill(
                      child: Image.memory(
                        snapshot.data,
                        fit: BoxFit.cover,
                      ),
                    ),
                    if (asset.type == AssetType.video)
                      const Align(
                        alignment: Alignment.bottomRight,
                        child: Padding(
                          padding: EdgeInsets.only(right: 5, bottom: 5),
                          child: Icon(
                            Icons.videocam,
                            color: Colors.white,
                          ),
                        ),
                      ),
                  ],
                );
              }
              return Container();
            },
          ),
        );
      }
      setState(() {
        _mediaList.addAll(temp);
        currentPage++;
      });
    } else {
      // fail
      /// if result is fail, you can call `PhotoManager.openSetting();`  to open android/ios applicaton's setting to get permission
    }
  }
  @override
  Widget build(BuildContext context) {
    return NotificationListener<ScrollNotification>(
      onNotification: (ScrollNotification scroll) {

         return _handleScrollEvent(scroll);
      },
      child: GridView.builder(
          itemCount: _mediaList.length,
          gridDelegate:
          const SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 3),
          itemBuilder: (BuildContext context, int index) {
            return _mediaList[index];
          }),
    );
  }
}

The following code not working,

Positioned.fill(
                      child: Image.memory(
                        snapshot.data,**//Error here**
                        fit: BoxFit.cover,
                      ),
                    ),

I have updated the dependencies to photo_manager 2.1.2 and changed required method accordingly.

Answer 1

Finally its working after Type Casting it.

snapshot.data as Uint8List,



Positioned.fill(
                      child: Image.memory(
                        snapshot.data! as Uint8List,
                        fit: BoxFit.cover,
                      ),
                    ),