我正在做一个基于firebase realtime的android应用程序。我可以在我的回收器视图中获得子节点的总和。但我也需要那些总价值的总和以外的回收者的看法。所需的总计可用，但不准确（正确）。此外，在我们滚动到底部之前，总计是不正确的。当我们上下滚动“回收器”视图时，它也会不断变化。这是我的密码activity:--

public class LookIncomeActivity<SharedPreference> extends AppCompatActivity {
    FirebaseDatabase myfire;
    DatabaseReference myRef;
    private FirebaseRecyclerOptions<category> options1;
    int earned = 0;
    int saved = 0;

    @Override
    public void onBackPressed() {
        Intent o;
        o = new Intent(LookIncomeActivity.this, MainActivity.class);
        startActivity(o);
        finish();
    }
    private String getUID() {
        FirebaseUser mUser = FirebaseAuth.getInstance().getCurrentUser();
        if (mUser != null) {
            String strUID = mUser.getUid();
            if (!TextUtils.isEmpty(strUID)) {
                return strUID;
            }
        }

        return "";

    }
    @SuppressLint("SetTextI18n")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_look_income);
        final TextView tvTopic = (TextView) findViewById(R.id.idTitle);
        final TextView tvEarned = (TextView) findViewById(R.id.idEarned);
        final TextView tvSpent = (TextView) findViewById(R.id.idSpent);
        final RecyclerView userlist = (RecyclerView) findViewById(R.id.idRecycle);
        Button btnCreate= (Button) findViewById(R.id.idCreate);
        Button btnDelete = (Button) findViewById(R.id.idDelete);
        myfire = FirebaseDatabase.getInstance();
        userlist.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false));

        //------------------------------------------
        final String strUID = getUID();
        if (TextUtils.isEmpty(strUID)) {
            //handle case of null UID
        }
        //-------------------------------
        btnCreate.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent o;
                o = new Intent(LookIncomeActivity.this, BudgetIncomeActivity.class);
                startActivity(o);
                finish();

            }
        });

        btnDelete.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

            }
        });

        //-------------------------------
        myRef = myfire.getReference().child("Data").child(strUID).child("Budget_Income");

//------------------------------------------
        Toast.makeText(LookIncomeActivity.this, "Please Wait a While !", Toast.LENGTH_LONG).show();

//-------------------------
        options1 = new FirebaseRecyclerOptions.Builder<category>()
                .setQuery(myRef, category.class)
                .build();

        final FirebaseRecyclerAdapter<category, holder1> adapter = new FirebaseRecyclerAdapter<category, holder1>(options1) {

            @SuppressLint("SetTextI18n")
            @Override
            protected void onBindViewHolder(final holder1 holder, final int i, @NotNull final category passage) {
                final String title = getRef(i).getKey();

                assert title != null;

                holder.btnAdd.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        Intent o;

                        o = new Intent(LookIncomeActivity.this, EntryIncomeActivity.class);
                        o.putExtra("Title", title);

                        startActivity(o);
                        finish();
                    }
                });

                myRef = myfire.getReference().child("Data").child(strUID).child("Budget_Income");
                myRef.child(title).addValueEventListener(new ValueEventListener() {

                    @Override
                    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                        int budget = 0;

                        if (dataSnapshot.getValue() == null) {
                            Toast.makeText(getApplicationContext(), "Data Not Available", Toast.LENGTH_LONG).show();
                        } else {

                            final String stData1 = (Objects.requireNonNull(dataSnapshot.child("stData1").getValue())).toString();
                            final String stData2 = (Objects.requireNonNull(dataSnapshot.child("stData2").getValue())).toString();
                            final String stData3 = (Objects.requireNonNull(dataSnapshot.child("stData3").getValue())).toString();
                            final String stData4 = (Objects.requireNonNull(dataSnapshot.child("stData4").getValue())).toString();

                            category basic = new category(stData1, stData2, stData3, stData4);
                            holder.tvOne.setText("Title"+"("+stData1+")");
                            holder.tvTwo.setText("Budget"+"("+stData4+")");
                            int amount = 0;
                            amount = (Integer.parseInt(stData4));
                            budget = amount;

                            myRef = myfire.getReference().child("Data").child(strUID).child("Entry_Income").child(title);
                            final int finalBudget = budget;

                            myRef.addValueEventListener(new ValueEventListener() {

                                @Override
                                public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                                    int sum = 0;

                                    for (DataSnapshot data : dataSnapshot.getChildren()) {
                                        String value = data.child("stData4").getValue(String.class);
                                        assert value != null;
                                        int total = 0;
                                        total = (Integer.parseInt(value));
                                        sum = sum + total;
                                    }
                                    holder.tvThree.setText("Earned"+"("+String.valueOf(sum)+")");
                                    holder.tvFour.setText("Target"+"("+String.valueOf(finalBudget - sum)+")");
                                    earned = (earned + sum);
                                    saved=(saved-sum);
                                    tvTopic.setText("Total:"+ "["+String.valueOf(earned)+ "]");

                                }

                                @Override
                                public void onCancelled(@NonNull DatabaseError databaseError) {
                                    throw databaseError.toException(); // never ignore errors
                                }
                            });

                        }

                    }

                    @Override
                    public void onCancelled(@NonNull DatabaseError error) {
                        throw error.toException(); // never ignore errors
                    }

                });

            }

            @NonNull
            @Override
            public holder1 onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
                View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.item1, parent, false);
                return new holder1(v);
            }

        };

      //===============================================================================================

        userlist.setAdapter(adapter);
        adapter.startListening();

    }

}

简言之，我want:- 1-grand 总计在回收器视图外，不滚动到底部。2-在上下滚动时，总计不应改变。
请给我举个例子。