问Flutter Firebase从文档引用列表中获取文档快照列表的流

EN

Stream getChatsFromRefs(List<DocumentReference> refs) {
    List<Stream<DocumentSnapshot>> chatSnapList =
        List<Stream<DocumentSnapshot>>();
    for (DocumentReference ref in refs) {
      chatSnapList.add(ref.snapshots());
    }

    return Rx.combineLatest(chatSnapList, (values) => values.last);
  }


class ChatList extends StatefulWidget {
  @override
  _ChatListState createState() => _ChatListState();
}

class _ChatListState extends State<ChatList> {
  @override
  Widget build(BuildContext context) {
    DocumentSnapshot userSnapshotData = Provider.of<DocumentSnapshot>(context);
    print("no error so far");
    return StreamBuilder<List<DocumentSnapshot>>(
        stream:
            DatabaseService().getChatsFromRefs(userSnapshotData.data()["refs"]),
        builder: (_, snapshot) {
          final documents = snapshot.data;
          return ListView.builder(
            itemCount: documents.length,
            itemBuilder: (_, index) => Text(documents[index]["name"]),
          );
        });
  }
}