Question

我正在尝试列出来自可序列化对象的数据，但它不起作用。

我列出了带有序列化对象的recyclerview的信息。传递给另一个活动时，recyclerview不会显示任何数据。

对不起我的英语。

MainActivity

private void onOrderProduct() {
    bOrder.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {


            Cart cart = new Cart();
            cart.setComida(tvTitle.getText().toString());
            cart.setPreco(tvTotal.getText().toString());
            cart.setQuantidade(tvQtd.getText().toString());

            Intent intent = new Intent(MainActivity.this, SecondActivity.class);
            intent.putExtra("cart", cart);
            startActivity(intent);
        }
    });
}

SecondActivity

public class SecondActivity extends AppCompatActivity {
RecyclerView rvCart;

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

    rvCart = (RecyclerView) findViewById(R.id.tela5recycler_view);
    rvCart.setHasFixedSize(true);

    LinearLayoutManager manager = new LinearLayoutManager(this);

    rvCart.setLayoutManager(manager);


    if (getIntent().getSerializableExtra("cart") != null) {


        Intent intent = getIntent();

        Cart cart = (Cart) intent.getSerializableExtra("cart");

        ArrayList<Cart> eList = new ArrayList<>() cart;
        Adapter adapter =new Adapter(getApplicationContext(), eList );
        rvCart.setAdapter(adapter);

    }

}
}

适配器

public class Adapter extends RecyclerView.Adapter<Adapter.ItemViewHolder> {

private Context context;
private ArrayList<Cart> itemList;

public Adapter(Context context, ArrayList<Cart> itemList){
    this.context = context;
    this.itemList = itemList;
}

@Override
public ItemViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    LayoutInflater inflater = LayoutInflater.from(parent.getContext());
    View view = inflater.from(parent.getContext())
            .inflate(R.layout.adapter_card, parent, false);

    ItemViewHolder itemViewHolder = new ItemViewHolder(view);
    return itemViewHolder;
}

@Override
public void onBindViewHolder(ItemViewHolder holder, int position) {

    Cart item = itemList.get(position);

    holder.tvQtdcard.setText(item.getQuantidade());
    holder.tvComidacard.setText(item.getComida());
    holder.tvPrecocard.setText(item.getPreco());

}



@Override
public int getItemCount() {
    if(itemList != null){
        return itemList.size();
    }
    return 0;
}
public static class ItemViewHolder extends RecyclerView.ViewHolder{

    public CardView cvItem;
    public TextView tvQtdcard, tvComidacard, tvPrecocard;

    public ItemViewHolder(View itemView) {
        super(itemView);
        cvItem = (CardView)itemView.findViewById(R.id.tela1_1_1_1_1card);
        tvQtdcard = (TextView)itemView.findViewById(R.id.tela5qtdcard);
        tvComidacard = (TextView)itemView.findViewById(R.id.tela5comidacard);
        tvPrecocard = (TextView)itemView.findViewById(R.id.tela5precocard);


    }
}
}

Cart.class Serializable

import java.io.Serializable;



public class Cart implements Serializable{

private static final long serialVersionUID = 42L;
private String comida;
private String quantidade;
private String preco;

public String getComida() {
    return comida;
}

public void setComida(String comida) {
    this.comida = comida;
}

public String getQuantidade() {
    return quantidade;
}

public void setQuantidade(String quantidade) {
    this.quantidade = quantidade;
}

public String getPreco() {
    return preco;
}

public void setPreco(String preco) {
    this.preco = preco;
}

public String toString(){
    return comida;
}




}

Answer 1

您遗失了adapter.notifyDataSetChanged()并且您正在传递空的arraylist eList

ArrayList<Cart> eList = new ArrayList<>();
eList.add(cart);
Adapter adapter =new Adapter(getApplicationContext(), eList );
rvCart.setAdapter(adapter);

传递序列化对象

解决方案1（Hackytack解决方案）

公共类CardListHolder实现Serializable { private ListcardList = new ArrayList＆lt;＆gt;（）;
```
public List<Card>getCardList(){
    return cardList;
}

public void setCardList(List<Card> cardList){
    this.cardList=cardList;
}
```
}

使用此持有者对象传递卡片列表
解决方案2

为Card对象实现Parcelable，它可以通过卡列表，但理解起来有点复杂。请尝试www.parcelabler.com自动生成Card的Parceable类。

Recyclerview没有显示可序列化的数据

1 个答案: