Question

我在Firestore，已订阅和列表中有2个收藏集。我想首先从第一个集合（已订阅）中过滤文档，以仅获取用户已订阅的文档，所以类似

FirebaseFirestore.instance.collection("subscribed").where("userId", isEqualTo: currentUser.uid).where("subscribed", isEqualTo: true).snapshots();

现在，一旦我从快照中获得了documentID，我想使用这些ID遍历那些特定列表并显示它们

我尝试过的是

StreamBuilder(
            stream: getSharedListsStreamSnapshot(context),
            builder: (context, snapshot) {
              if (!snapshot.hasData)
                return SpinKitDoubleBounce(color: Colors.black);
              else
              return new ListView.builder(
                  shrinkWrap: true,
                  itemCount: snapshot.data.docs.lenght,
                  itemBuilder: (BuildContext context, int index) =>
                      buildHomeViewCard2(context, snapshot.data.docs[index]));
            }),

Stream<QuerySnapshot> getSharedListsStreamSnapshot(
      BuildContext context) async* {
    final uid = await Provider.of(context).auth.getCurrentUID();
    await FirebaseFirestore.instance
        .collection("subscribed")
        .where("userId", isEqualTo: uid)
        .where("subscribed", isEqualTo: true)
        .get()
        .then((val) {
      FirebaseFirestore.instance
          .collection("subscribed")
          .where("userId", isEqualTo: uid)
          .where("subscribed", isEqualTo: true)
          .get()
          .then((event) {
        event.docs.forEach((element) {
          FirebaseFirestore.instance
              .collection("lists")
              .where("id", isEqualTo: element['listId'])
              .snapshots();
          print(element['listId']);
        });
      });
    });
 Widget buildHomeViewCard2(
      BuildContext context, DocumentSnapshot documentSnapshot) {
    final lists = Lists.fromSnapshot(documentSnapshot);
    final listIcon = lists.iconForList();
    return Container(
      child: InkWell(
        child: Padding(
          padding: const EdgeInsets.all(10.0),
          child: ListTile(
            leading: (listIcon.containsKey(lists.icon))
                ? listIcon[lists.icon]
                : listIcon["list"],
            title: Text(
              lists.name,
              style: new TextStyle(fontSize: 20.0),
            ),
          ),
        ),
        onTap: () {
          Navigator.push(
              context,
              MaterialPageRoute(
                builder: (context) => TasksView(
                  lists: list,
                ),
              ));
        },
      ),
    );
  }
 }

它会打印元素['listId']，但不会在ui上显示任何列表。

感谢您的帮助谢谢

Flutter Firestore：是否可以根据其他收藏的文档获取其他收藏的文档？

0 个答案: