Как без ошибок перейти к следующему добавленному элементу в FirebaseRecyclerAdapter? - PullRequest
0 голосов
/ 26 января 2020

Я создаю приложение для чата. Когда я в нижней части FirebaseRecyclerView, и когда он обновляется из базы данных, приложение вылетает. Когда я нахожусь в другом месте в обзоре переработчика, он прокручивается вниз, но не внизу. Вот мой код:

FirebaseRecyclerOptions<Messages> options = new FirebaseRecyclerOptions.Builder<Messages>()
                .setQuery(query, Messages.class)
                .build();

        FBRA = new FirebaseRecyclerAdapter<Messages, MessageViewHolder>(options) {

            @Override
            protected void onBindViewHolder(@NonNull MessageViewHolder holder, int position, @NonNull Messages model) {
                    holder.setTime(model.getTime()); //getting error here
                }
                else {

                }
            }

            @NonNull
            @Override
            public MessageViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
                View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.chat_card, parent, false);
                return new MessageViewHolder(view);
            }
        };
        FBRA.startListening();
        FBRA.notifyDataSetChanged();
        FBRA.registerAdapterDataObserver(new RecyclerView.AdapterDataObserver() {

            @Override
            public void onItemRangeChanged(int positionStart, int itemCount, @Nullable Object payload) {
                rvllm.scrollToPosition(FBRA.getItemCount()-1);
            }

            @Override
            public void onItemRangeMoved(int fromPosition, int toPosition, int itemCount) {
                rvllm.scrollToPosition(FBRA.getItemCount()-1);
            }

            @Override
            public void onItemRangeInserted(int positionStart, int itemCount) {
                rvllm.scrollToPosition(FBRA.getItemCount()-1);
            }
        });
        messages.setAdapter(FBRA);

Ошибка:

Process: , PID: 32348
    java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference
        at com.ChatActivity.onBindViewHolder(ChatActivity.java:123)
        at com.ChatActivity$2.onBindViewHolder(ChatActivity.java:118)
        at com.firebase.ui.database.FirebaseRecyclerAdapter.onBindViewHolder(FirebaseRecyclerAdapter.java:149)
        at androidx.recyclerview.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6781)
        at androidx.recyclerview.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6823)
        at androidx.recyclerview.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5752)
        at androidx.recyclerview.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:6019)
        at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5858)
        at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5854)
        at androidx.recyclerview.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2230)
        at androidx.recyclerview.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1557)
        at androidx.recyclerview.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1517)
        at androidx.recyclerview.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:587)
        at androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3924)
        at androidx.recyclerview.widget.RecyclerView.dispatchLayout(RecyclerView.java:3641)
        at androidx.recyclerview.widget.RecyclerView.onLayout(RecyclerView.java:4194)
        at android.view.View.layout(View.java:21916)
        at android.view.ViewGroup.layout(ViewGroup.java:6260)
        at androidx.constraintlayout.widget.ConstraintLayout.onLayout(ConstraintLayout.java:1915)
        at android.view.View.layout(View.java:21916)
        at android.view.ViewGroup.layout(ViewGroup.java:6260)
        at android.widget.FrameLayout.layoutChildren(FrameLayout.java:332)
        at android.widget.FrameLayout.onLayout(FrameLayout.java:270)
        at android.view.View.layout(View.java:21916)
        at android.view.ViewGroup.layout(ViewGroup.java:6260)
        at androidx.appcompat.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:446)
        at android.view.View.layout(View.java:21916)
        at android.view.ViewGroup.layout(ViewGroup.java:6260)
        at android.widget.FrameLayout.layoutChildren(FrameLayout.java:332)
        at android.widget.FrameLayout.onLayout(FrameLayout.java:270)
        at android.view.View.layout(View.java:21916)
        at android.view.ViewGroup.layout(ViewGroup.java:6260)
        at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1829)
        at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1673)
        at android.widget.LinearLayout.onLayout(LinearLayout.java:1582)
        at android.view.View.layout(View.java:21916)
        at android.view.ViewGroup.layout(ViewGroup.java:6260)
        at android.widget.FrameLayout.layoutChildren(FrameLayout.java:332)
        at android.widget.FrameLayout.onLayout(FrameLayout.java:270)
        at com.android.internal.policy.DecorView.onLayout(DecorView.java:779)
        at android.view.View.layout(View.java:21916)
        at android.view.ViewGroup.layout(ViewGroup.java:6260)
        at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:3081)
        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2591)
        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1722)
        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7605)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:1041)
        at android.view.Choreographer.doCallbacks(Choreographer.java:864)
        at android.view.Choreographer.doFrame(Choreographer.java:799)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:1026)
        at android.os.Handler.handleCallback(Handler.java:883)
        at android.os.Handler.dispatchMessage(Handler.java:100)
2020-01-26 02:27:42.540 32348-32348/ E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7397)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:935)
...