java - 火力地堡用户界面 : Solution to receive all keys from a child and use it to receive information from another node and fill it in a Recyclerview?

Question

我正在寻找一种解决方案来从我的 child “药物”中获取数据，并使用 ID 从“medication_plan”节点接收特定数据并将它们显示在 Recyclerview 中。

数据库结构:

目前我正在使用 Firebase UI 来填充我的 Recyclerview

private DatabaseReference mRef;

private RecyclerView mRecyclerView;
private RecyclerView.LayoutManager mLayoutManager;
private FirebaseRecyclerAdapter<Medication,MedicationViewHolder> mAdapter;

List<User> items = new ArrayList<>();

User user = new User();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mRecyclerView = findViewById(R.id.my_recycler_view);
    mRecyclerView.setHasFixedSize(true);

    mLayoutManager = new LinearLayoutManager(this);
    mRecyclerView.setLayoutManager(mLayoutManager);

    setData();
}

private void setData() {
    Query query = FirebaseDatabase.getInstance().getReference().child("Medication_plan");
    FirebaseRecyclerOptions<Medication> options = new FirebaseRecyclerOptions.Builder<Medication>()
            .setQuery(query,Medication.class)
            .build();

    mAdapter = new FirebaseRecyclerAdapter<Medication, MedicationViewHolder>(options) {
        @Override
        protected void onBindViewHolder(@NonNull MedicationViewHolder holder, int position, @NonNull Medication model) {
            final Medication tempmed = new Medication(model.getDr()
                    ,model.getMedicine()
                    ,model.getDate()
                    ,model.getComment());

            holder.mDoctor.setText(model.getDr());
            holder.mMedicine.setText(model.getMedicine());
            holder.mDate.setText(model.getDate());
        }

        @NonNull
        @Override
        public MedicationViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
            View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.my_text_view,viewGroup,false);
            MedicationViewHolder vh = new MedicationViewHolder(v);
            return vh;
        }
    };

    mRecyclerView.setAdapter(mAdapter);
}

@Override
protected void onStart() {
    mAdapter.startListening();
    super.onStart();
}

@Override
protected void onStop() {
    mAdapter.stopListening();
    super.onStop();
}

当我使用此代码时，我得到了每个药物计划，但我只想要用户提供的具体计划。

Answer 1

添加此函数以获取您的数据:

ArrayList<String> list = new ArrayList<String>();
DatabaseReference ref= FirebaseDatabase.getInstance().getReference("User").child("R3").child("medication");
ref.addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        for (DataSnapshot snap: dataSnapshot.getChildren()) {
            list.add(snap.child("id").getValue(String.class));
        }
    }

    @Override
    public void onCancelled(DatabaseError databaseError) {
        Log.w(TAG, "onCancelled", databaseError.toException());
    }
});

之后添加此代码以获取第二个数据信息:

ArrayList<String> listOfSomething = new ArrayList<String>();
DatabaseReference ref=  FirebaseDatabase.getInstance().getReference("Medication_plan");
ref.addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        for (String s: list) {
            listOfSomething.add(dataSnapshot.child("s").child("comment").getValue(String.class));
        }
    }

    @Override
    public void onCancelled(DatabaseError databaseError) {
        Log.w(TAG, "onCancelled", databaseError.toException());
    }
});

在我的示例中，我检索了评论。您可以将其更改为您想要检索的任何内容。