Can help me to delete data from firebase and recyclerView?

问题

I did recyclerView retrieve data from firebase real-time database, and created button for delete item from recycelerView and from database I have 2 questions

1- after i add new item in recyclerView and then try delete it not delete directly , just when add item and run code again then i can delete it

---

public class WorkerRecyclerViewAdapter extends RecyclerView.Adapter<WorkerRecyclerViewAdapter.ViewHolder> {

private Context context;
private ArrayList<Worker> workersList;

private onItemClickListener mListener;

public WorkerRecyclerViewAdapter(Context context, ArrayList <Worker> workersList) {
    this.context = context;
    this.workersList = workersList;
}

@NonNull
@Override
public WorkerRecyclerViewAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.worker_card,parent,false);
    return new ViewHolder(view);
}

@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
     final Worker worker = this.workersList.get(position);
    holder.name.setText(workersList.get(position).getName());
    holder.phone.setText(workersList.get(position).getPhone());

    holder.deleteWorker.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReference("Employees").child(worker.getPhone());
            databaseReference.removeValue();
        }
    });

}

@Override
public int getItemCount() {
    return workersList.size();
}

public class ViewHolder extends RecyclerView.ViewHolder{

    TextView name,phone;
    ImageView deleteWorker;
    public ViewHolder(@NonNull View itemView) {
        super(itemView);

        name = itemView.findViewById(R.id.name);
        phone = itemView.findViewById(R.id.phone);
        deleteWorker = itemView.findViewById(R.id.delete_worker);
    }
}

}

---

add data to recycler view (java)

  final FirebaseDatabase database = FirebaseDatabase.getInstance();
    final DatabaseReference table_employee = database.getReference("Employees");

    addWorker.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            final ProgressDialog dialog = new ProgressDialog(Add_worker.this);
            dialog.setMessage("انتظر!");
            dialog.show();

            if (name.length()==0){
                dialog.dismiss();
                name.setError("ادخل اسمك");
            }else if (phone.length()==0){
                dialog.dismiss();
                phone.setError("ادحل رقم تليفونك");
            }else{

                table_employee.addValueEventListener(new ValueEventListener() {
                    @Override
                    public void onDataChange(@NonNull DataSnapshot snapshot) {
                        //check if already phone exist
                        if (snapshot.child(phone.getText().toString()).exists()){
                            dialog.dismiss();
                            Toast.makeText(Add_worker.this, "انت مسجل من قبل", Toast.LENGTH_LONG).show();
                        }else{
                            dialog.dismiss();
                            Worker user = new Worker(name.getText().toString(),phone.getText().toString());
                            table_employee.child(phone.getText().toString()).setValue(user);
                            Toast.makeText(Add_worker.this, "تم التسجيل بنجاح", Toast.LENGTH_LONG).show();

                            Intent intent =new Intent(Add_worker.this,Workerr.class);
                            startActivity(intent);
                            finish();
                        }

                    }

                    @Override
                    public void onCancelled(@NonNull DatabaseError error) {

                    }
                });
            }}

---

recyclerView page (java)

recyclerView_worker = findViewById(R.id.worker_recyclerView);
    LinearLayoutManager layoutManager =new LinearLayoutManager(this);
    recyclerView_worker.setLayoutManager(layoutManager);
    recyclerView_worker.setHasFixedSize(true);

    databaseReference = FirebaseDatabase.getInstance().getReference();

    workerList = new ArrayList <>();
    ClearList();

    GetDataFromFirebase();
}

private void GetDataFromFirebase() {

    Query query = databaseReference.child("Employees");
    query.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
            ClearList();
            for (DataSnapshot snapshot: dataSnapshot.getChildren()){
                Worker worker = new Worker();
                worker.setName(snapshot.child("name").getValue().toString());
                worker.setPhone(snapshot.child("phone").getValue().toString());
                workerList.add(worker);
            }
            workerRecyclerViewAdapter = new WorkerRecyclerViewAdapter(getApplicationContext(),workerList);
            recyclerView_worker.setAdapter(workerRecyclerViewAdapter);
            workerRecyclerViewAdapter.notifyDataSetChanged();
        }

        @Override
        public void onCancelled(@NonNull DatabaseError error) {

        }
    });

}

private void ClearList(){
    if (workerList != null){
        workerList.clear();

        if (workerRecyclerViewAdapter != null){
            workerRecyclerViewAdapter.notifyDataSetChanged();
        }
    }
    workerList= new ArrayList <>();
}

---

Workers page (java)

public class Worker {

private String name;
private String phone;

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getPhone() {
    return phone;
}

public void setPhone(String phone) {
    this.phone = phone;
}

public Worker() {
}

public Worker(String name, String phone) {
    this.name = name;
    this.phone = phone;
}

}

2- the key in child is same the value of this child ex: when user add phone is added as key and value [enter image description here][1] [1]: https://i.stack.imgur.com/FJfzc.jpg

Please help please Thanks in advance

来源：https://stackoverflow.com/questions/65947463/how-can-i-delete-data-from-database-before-close-app