从 FirestoreRecyclerView 向 recyclerview 添加多个项目答案

【问题标题】：Add multiple items to recyclerview from FirestoreRecyclerView从 FirestoreRecyclerView 向 recyclerview 添加多个项目
【发布时间】：2018-10-10 01:50:24
【问题描述】：

我将我的应用程序连接到 Firestore，并且我有一个名为 timey 的字符串，它是一个被选择的日期（与如何选择无关）并与 Firestore 文档中的字符串 timey 进行比较。

我成功地让应用程序将 Firestore 输出显示到 TextView，但如果我有 2 个具有相同日期的条目，它总是会选择一个而忘记另一个。所以我决定尝试使用FirebaseRecyclerAdapter 显示数据，它通常会显示“单个日期条目”，但是一旦我选择一个包含 2 个条目的日期，它就会使应用程序崩溃。这是源代码，知道如何让 RecyclerView 显示数十个具有相同日期的条目，并将它们都作为单独的条目放在 RecyclerView 中吗？

... passArg 是从不同布局传递的日期。

static String passedArg;
RecyclerView reserveList;
private static final CollectionReference reservationCollection = FirebaseFirestore.getInstance().collection("reservations");
private static Query reservationsQuery;

private FirebaseFirestore db;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_page);
    textView = findViewById(R.id.textView);
    textView2 = findViewById(R.id.textView2);
    textView3 = findViewById(R.id.textView3);
    passedArg = getIntent().getExtras().getString(MESSAGE_KEY);
    textView.setText(passedArg);
    reservationsQuery = reservationCollection.whereEqualTo("timey", passedArg);
    RecyclerView reserveList = (RecyclerView) findViewById(R.id.reserveList);
    reserveList.setLayoutManager(new LinearLayoutManager (this));
    FirestoreRecyclerOptions<Reservations> options =
            new FirestoreRecyclerOptions.Builder<Reservations>()
                    .setQuery(reservationsQuery, Reservations.class)
                    .setLifecycleOwner(this)
                    .build();
    FirestoreRecyclerAdapter<Reservations, ReservationsHolder> adapter = new FirestoreRecyclerAdapter<Reservations, ReservationsHolder>(options) {
        @Override
        protected void onBindViewHolder(@NonNull ReservationsHolder holder, int position, @NonNull Reservations model) {
            holder.setName(model.getName());
            holder.setTime(model.getTime());
            holder.setCountry(model.getCountry());
            }


        @NonNull
        @Override
        public ReservationsHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
            return new ReservationsHolder(LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.reservations, parent, false));
        }
    };
        reserveList.setAdapter(adapter);

如果您需要更多代码，请告诉我。

编辑：崩溃日志：

E/AndroidRuntime: FATAL EXCEPTION: main
              Process: com.nedim.calendar1, PID: 10342
              java.lang.RuntimeException: Could not deserialize object. Failed to convert value of type java.util.Date to String (found in field 'time')
                  at com.google.android.gms.internal.firebase-firestore.zzko.zzb(Unknown Source)
                  at com.google.android.gms.internal.firebase-firestore.zzko.zza(Unknown Source)
                  at com.google.android.gms.internal.firebase-firestore.zzko.zza(Unknown Source)
                  at com.google.android.gms.internal.firebase-firestore.zzko.zzb(Unknown Source)
                  at com.google.android.gms.internal.firebase-firestore.zzko$zza.zza(Unknown Source)
                  at com.google.android.gms.internal.firebase-firestore.zzko.zza(Unknown Source)
                  at com.google.android.gms.internal.firebase-firestore.zzko.zza(Unknown Source)
                  at com.google.firebase.firestore.DocumentSnapshot.zza(Unknown Source)
                  at com.google.firebase.firestore.QueryDocumentSnapshot.zza(Unknown Source)
                  at com.google.firebase.firestore.DocumentSnapshot.toObject(Unknown Source)
                  at com.google.firebase.firestore.QueryDocumentSnapshot.toObject(Unknown Source)
                  at com.firebase.ui.firestore.ClassSnapshotParser.parseSnapshot(ClassSnapshotParser.java:23)
                  at com.firebase.ui.firestore.ClassSnapshotParser.parseSnapshot(ClassSnapshotParser.java:12)
                  at com.firebase.ui.common.BaseCachingSnapshotParser.parseSnapshot(BaseCachingSnapshotParser.java:35)
                  at com.firebase.ui.common.BaseObservableSnapshotArray.get(BaseObservableSnapshotArray.java:52)
                  at com.firebase.ui.firestore.FirestoreRecyclerAdapter.getItem(FirestoreRecyclerAdapter.java:83)
                  at com.firebase.ui.firestore.FirestoreRecyclerAdapter.onBindViewHolder(FirestoreRecyclerAdapter.java:125)
                  at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6673)
                  at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6714)
                  at android.support.v7.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5647)
                  at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5913)
                  at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5752)
                  at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5748)
                  at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2232)
                  at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1559)
                  at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1519)
                  at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:614)
                  at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3812)
                  at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:3529)
                  at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:4082)
                  at android.view.View.layout(View.java:17572)
                  at android.view.ViewGroup.layout(ViewGroup.java:5656)
                  at android.support.constraint.ConstraintLayout.onLayout(ConstraintLayout.java:1855)
                  at android.view.View.layout(View.java:17572)
                  at android.view.ViewGroup.layout(ViewGroup.java:5656)
                  at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
                  at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
                  at android.view.View.layout(View.java:17572)
                  at android.view.ViewGroup.layout(ViewGroup.java:5656)
                  at android.support.v7.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:443)
                  at android.view.View.layout(View.java:17572)
                  at android.view.ViewGroup.layout(ViewGroup.java:5656)
                  at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
                  at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
                  at android.view.View.layout(View.java:17572)
                  at android.view.ViewGroup.layout(ViewGroup.java:5656)
                  at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1741)
                  at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1585)
                  at android.widget.LinearLayout.onLayout(LinearLayout.java:1494)
                  at android.view.View.layout(View.java:17572)
                  at android.view.ViewGroup.layout(ViewGroup.java:5656)
                  at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
                  at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
                  at com.android.internal.policy.DecorView.onLayout(DecorView.java:755)
                  at android.view.View.layout(View.java:17572)
                  at android.view.ViewGroup.layout(ViewGroup.java:5656)
                  at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2429)
                  at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2149)
                  at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1306)
                  at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6579)
                  at android.view.Choreographer$CallbackRecord.run(Choreographer.java:871)
                  at android.view.Choreographer.doCallbacks(Choreographer.java:683)
                  at android.view.Choreographer.doFrame(Choreographer.java:619)
                  at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:857)
                  at android.os.Handler.handleCallback(Handler.java:751)
                  at android.os.Handler.dispatchMessage(Handler.java:95)
                  at android.os.Looper.loop(Looper.java:154)
                  at android.app.ActivityThread.main(ActivityThread.java:6316)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:872)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:762)
W/Firestore: (0.6.6-dev) [OnlineStateTracker]: Could not reach Firestore backend.

【问题讨论】：

标签： java android firebase android-recyclerview google-cloud-firestore

【解决方案1】：

您收到以下错误：

java.lang.RuntimeException: Could not deserialize object. Failed to convert value of type java.util.Date to String (found in field 'time')

因为在您的 Firestore 数据库中，您有一个名为 time 的属性，其类型为 Date 而不是字符串。所以要解决这个问题，请参阅how you can store the server timestamp in a Firestore database 以及如何正确地format 它。

如果您有兴趣，this 是您可以正确地从 Cloud Firestore 数据库中检索数据并使用 FirestoreRecyclerAdapter 将其显示在 RecyclerView 中的方法。

【讨论】：