Firebase task.snapshotEvents.listen StateProvider 未获取更新的上传进度

Question

我应用中的所有屏幕都可以访问上传状态提供程序。当我从上传屏幕上传对象时，我使用 FlutterFire Handling Tasks 获取上传进度。

上传任务工作正常，但是当我从上传屏幕导航到主屏幕时，我正在显示上传 StateProvider 的进度，它只显示当前进度，并没有获取更新发生在背景.

如何配置 RiverPod 以仍然监听后台快照运行或者我应该避免为此使用 RiverPod 而只使用 Firebase 存储监听器？

正在上传 StateProvider

final uploadingStateProvider = StateProvider<String?>((ref) => null);

Firebase 存储上传任务正在向我的 StateProvider 发送进度字符串

task.snapshotEvents.listen((TaskSnapshot snapshot) {
  if (displayProgressNotification) {
    final int percent =
        ((snapshot.bytesTransferred / snapshot.totalBytes) * 100).round();
    if (percent >= 100) {
      context.read(uploadingStateProvider).state = null;
    } else {
      context.read(uploadingStateProvider).state =
          percent.toString();
    }
  } else {
    context.read(uploadingStateProvider).state = null;
  }
}, onDone: () async {
  context.read(uploadingStateProvider).state = null;
  if (deleteAfterUpload) {
    await file.delete();
  }
}, onError: (e) {
  context.read(uploadingStateProvider).state = null;
  debugPrint(task.snapshot.toString());
  debugPrint(e.toString());
});

主屏幕显示带有百分比的进度微调器，但它只显示它读取的初始百分比，不会从后台任务获取更新的百分比

Consumer(
  builder: (context, watch, child) {
    final uploadingPercent =
        watch(uploadingStateProvider).state;
    if (uploadingPercent != null) {
      return Stack(
        alignment: Alignment.center,

        /// Note: First child is the bottom of the stack...
        children: [
          SpinKitDualRing(
            color: Colors.white.withOpacity(0.5),
            size: titleFontSize(shrinkOffset),
            lineWidth: 2.0,
            duration: const Duration(
                milliseconds: 1500),
          ),
          Text(
            '$uploadingPercent%',
            style: TextStyle(
              color: Colors.white.withOpacity(0.5),
              fontSize: uploadFontSize(shrinkOffset),
              fontWeight: FontWeight.w200,
            ),
          ),
        ],
      );
    } else {
      return const SizedBox.shrink();
    }
  },
),

Answer 1

我会使用 1.0.0 版本。没有上下文

final uploadingStateProvider =
    StateNotifierProvider.autoDispose<UploadingState, int?>((ref) {
  return UploadingState(read: ref.read);
});

我会使用 StateNotifier。如果您想要 myUploadTask 方法中的整个逻辑，reader 会很有用。

class UploadingState extends StateNotifier<int?> {
  final Reader read;
  StreamSubscription? mySubscription;

  UploadingState({required this.read}) : super(null);

  Future<void> myUploadTask(firebase_storage.UploadTask task) async {
    mySubscription = task.snapshotEvents.listen((TaskSnapshot snapshot) {
      final int percent =
          ((snapshot.bytesTransferred / snapshot.totalBytes) * 100).round();
      state = percent;
    }, onDone: () async {
      state = null;
    }, onError: (e) {
      state = null;
      debugPrint(task.snapshot.toString());
      debugPrint(e.toString());
    });
  }

  @override
  void dispose() {
    mySubscription?.cancel();
    super.dispose();
    
  }
}

还有你的消费者

Consumer(
  builder: (context,  ref,_) {
    final uploadingPercent = ref.watch(uploadingStateProvider);
    if (uploadingPercent != null) {
      return Stack(
        alignment: Alignment.center,

        /// Note: First child is the bottom of the stack...
        children: [
          SpinKitDualRing(
            color: Colors.white.withOpacity(0.5),
            size: titleFontSize(shrinkOffset),
            lineWidth: 2.0,
            duration: const Duration(
                milliseconds: 1500),
          ),
          Text(
            '$uploadingPercent%',
            style: TextStyle(
              color: Colors.white.withOpacity(0.5),
              fontSize: uploadFontSize(shrinkOffset),
              fontWeight: FontWeight.w200,
            ),
          ),
        ],
      );
    } else {
      return const SizedBox.shrink();
    }
  },
),

在某处调用或将所有逻辑放入 UploadingState()

ref.read(uploadingStateProvider.notifier).myUploadTask(task);

Firebase task.snapshotEvents.listen StateProvider 未获取更新的上传进度

Firebase task.snapshotEvents.listen StateProvider not getting updated progress for upload

flutter

riverpod