RecyclerView 不更新

Question

My MainActivity has a recyclerview that will receive the products. In the floatActionButton of MainActivity and I call AddActivity which has the fields to add the product, including a recycler where I insert inputs to compose the price. the problem is exactly in the AddActivity recyclerView

I have a simple recyclerView and the adapter below where I do the CRUD before saving to the database, and everything works except the update, where I update the item through the adapter but the view in the list does not update the data. If you click on the same item to edit it again it shows the values that have already been updated and not those shown in the list.

Below my adapter:

public class InsumoAdapter extends RecyclerView.Adapter<InsumoAdapter.InsumoViewHolder>{

   
    private final Context context;
    private List<Insumo> insumos;


    public InsumoAdapter(Context context, List<Insumo> insumos) {
        this.context = context;
        this.insumos = insumos;
    }

    @Override
    public InsumoAdapter.InsumoViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        View view = LayoutInflater.from(context).inflate(R.layout.card_teste, viewGroup, false);
        InsumoAdapter.InsumoViewHolder holder = new InsumoAdapter.InsumoViewHolder(view);
        return holder;
    }

    public static class InsumoViewHolder extends RecyclerView.ViewHolder{
        public TextView tNome, tVlrCusto;
        ImageButton btnDelete;
        CardView cardView;
        public InsumoViewHolder(View view){
            super(view);
            tNome = (TextView) view.findViewById(R.id.txtNomeProd);
            tVlrCusto = (TextView) view.findViewById(R.id.txtValorProd);
            btnDelete = (ImageButton) view.findViewById(R.id.imgBtnDel);
            cardView = (CardView) view.findViewById(R.id.cardProduto);
        }
    }

    @Override
    public void onBindViewHolder(final InsumoViewHolder holder, final int position) {
        if(insumos.size() != 0){
            final Insumo p = insumos.get(position);
            holder.tNome.setText(p.getNomeInsumo());
            holder.tVlrCusto.setText(p.getValor().toString());

            holder.cardView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Toast.makeText(context, "Clicou no Card para Editar na posição "+position,Toast.LENGTH_SHORT).show();
                    Bundle bundle = new Bundle();
                    //bundle.putString("nome", p.getNomeInsumo());
                    //bundle.putDouble("valor", p.getValor());
                    bundle.putInt("position", position);
                    Intent intent = new Intent(context, UpdateActivity.class);
                    intent.putExtras(bundle);
                    context.startActivity(intent);
                    //update(p, position);
                }
            });

            holder.btnDelete.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Toast.makeText(context, "Clicou no Card para Excluir na posição "+position,Toast.LENGTH_SHORT).show();
                    delete(position);
                }
            });
        }
    }

    @Override
    public int getItemCount() {
        return this.insumos != null ? this.insumos.size() : 0;
    }


    private void excluirInsumo(Context context, final int i){
        String titulo = "Excluir";
        String msg = "Deseja excluir este item?";
        AlertDialog alertDialog = new AlertDialog.Builder(context).create();
        alertDialog.setTitle(titulo);
        alertDialog.setMessage(msg);
        alertDialog.setButton(AlertDialog.BUTTON_POSITIVE, "Sim",
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        //deleta("Pproduto",produtos.get(i).get_id());
                        AddActivity addActivity = new AddActivity();
                        //addActivity.deleta(i);

                        dialog.dismiss();
                    }
                });
        alertDialog.setButton(AlertDialog.BUTTON_NEGATIVE, "Não",
                new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
                    }
                });
        alertDialog.show();
    }

    private void delete(int position){
        insumos.remove(position);
        notifyItemRemoved(position);
    }

    public void update(Insumo insumo, int position){
        insumos.set(position, insumo);
        //notifyItemChanged(position);
        notifyDataSetChanged();
    }

    public void insere(Insumo insumo){
        insumos.add(insumo);
        notifyDataSetChanged();
    }

It's like not going back to onBindViewHolder to update the data. Could someone give me a light? If you need something, but you can't find any way.

Editing-----

AddActivity

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

        edtNome = (TextInputEditText) findViewById(R.id.edtNome);
        valorCusto = (TextView) findViewById(R.id.txtValorCustoAdd);
        valorVenda = (TextView) findViewById(R.id.txtValorVendaAdd);
        valorPerc = (TextView) findViewById(R.id.txtValorPercAdd);
        addItem = (FloatingActionButton) findViewById(R.id.fltBtnAddItem);
        addFoto = (FloatingActionButton) findViewById(R.id.fltBtnAddFoto);
        salvar = (FloatingActionButton) findViewById(R.id.fltBtnSalvar);
        imgFoto = (ImageView) findViewById(R.id.imgFoto);
        recyclerView = (RecyclerView) findViewById(R.id.recy);

        edtNome.setTextIsSelectable(true);

        valorCusto.setText(valor.toString());
        valorPerc.setText("0");

        recyclerView.setLayoutManager(new LinearLayoutManager(getApplicationContext()));
        recyclerView.setItemAnimator(new DefaultItemAnimator());
        recyclerView.setHasFixedSize(true);

        InsumoAdapter insumoAdapter = new InsumoAdapter(getApplicationContext(), insumos);

        recyclerView.setAdapter(insumoAdapter);
        insumoAdapter.notifyDataSetChanged();

        addItem.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(getApplication(), InsertActivity.class);
                startActivity(intent);
            }
        });

        salvar.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Produto produto = new Produto();
                produto.setpNome(edtNome.getText().toString());
                produto.setpValorCusto(somaValor(insumos));
                if(foto == 0){
                    produto.setPfoto(R.drawable.noimage);
                }else{
                    produto.setPfoto(foto);
                }
            }
        });
    }

Activity of insumo's insert

update.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                insumo = new Insumo();
                insumo.setNomeInsumo(nome.getText().toString());
                Log.d(TAG, getClass()+" insumo.getNome = "+insumo.getNomeInsumo());
                insumo.setValor(Double.parseDouble(valor.getText().toString()));
                Log.d(TAG, getClass()+" insumo.getValor = "+insumo.getValor());
                AddActivity addActivity = new AddActivity();
                //addActivity.update(insumo, pos);
                InsumoAdapter insumoAdapter = new InsumoAdapter(getBaseContext(), addActivity.lista());
                insumoAdapter.update(insumo, pos);
                insumoAdapter.notifyDataSetChanged();
                finish();
            }
        });

MainAcitvity

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

        recyclerView = (RecyclerView) findViewById(R.id.recyclerTeste);
        FloatingActionButton btn = (FloatingActionButton) findViewById(R.id.fltBtnAdd);

        recyclerView.setLayoutManager(new LinearLayoutManager(getApplicationContext()));
        recyclerView.setItemAnimator(new DefaultItemAnimator());
        recyclerView.setHasFixedSize(true);

        ProdutoAdapter produtoAdapter = new ProdutoAdapter(getBaseContext(), produtos);

        recyclerView.setAdapter(produtoAdapter);
        produtoAdapter.notifyDataSetChanged();


        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(MainActivity.this, AddActivity.class);
                startActivity(intent);
            }
        });

Answer 1

Instead of creating a new Adapter, just use the current adapter instance and use it for update and notifyDataSetChanged.

public InsumoAdapter insumoAdapter;

// Inside onCreate
@Override
protected void onCreate(Bundle savedInstanceState) {
    ....
    insumoAdapter = new InsumoAdapter(getApplicationContext(), insumos);
    ....
}

// Inside Update onClick
update.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
    ....
    insumoAdapter.update(insumo, pos)
    insumoAdapter.notifyDataSetChanged()
}

Answer 2

The problem is; you're creating a new instance of adapter instead of using the adapter attached to your recyclerView . Please use the same instance of adapter that's attached to your recyclerView.

In your Activity where your recyclerView is instantiated, use a member reference to contain your reference. ie mInsumoAdapter

Then when you create your first adapter instance and attach it to your recyclerView, assign it to mInsumoAdapter .

Finally use the same reference to call your update method.

mInsumoAdapter.update(insumo, pos);

For sharing references between activities and services, you can create a common sharing class like this:

public class ReferenceUtil {
    private static InsumoAdapter insumoAdapter;

    public static InsumoAdapter getMainAdapter(){
        return insumoAdapter;
    }

    public static void setMainAdapter(InsumoAdapter adapter) {
        insumoAdapter = adapter;
    }
}

Then use ReferenceUtil.setMainAdapter(adapter); when you click on your FAB, and on your next activity use ReferenceUtil.getMainAdapter(); to obtain your attached reference and update that for your recyclerView to get updated on runtime.

Remember to set the static insumoAdapter in ReferenceUtil to null when you return back to your previous activity because it could lead to a memory leak in your application.

Answer 3

Try with using notifyDataSetChnaged() in the activity from where you are passing the list to the adapter or you could do it after updating it. something like this,

RecyclerView.setAdapter(this,list);
notifyDataSetChanged();

or

InsumoAdapter.update(list,pos);
notifyDataSetChanged();

You could try use this way for all the CRUD operations.