从 RecyclerView 检索数据

Question

我在使用自定义适配器的应用程序中使用 RecyclerView。我想处理现有菜单 RecyclerView 项。像普通变量一样访问它们，以便我可以应用特定条件或将它们发送到我的 Class 适配器之外的文本消息中等等。

如何访问 RecyclerView 项？

代码class矩阵：

public class MainActivity extends AppCompatActivity {

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

        addItem();

        Button button = findViewById(R.id.get_item);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                /*
                    I want when I press the button
                    The items are called
                 */
            }
        });

    }

    public void addItem() {

        List<Shops> shops = new ArrayList<>();
        String[] cloth = {"Silk", "Cotton", "Linen"};
        String[] wood = {"Sandal", "Jawi", "Pine"};
        String[] metal = {"Window", "door", "roof"};

        RecyclerView recyclerView = findViewById(R.id.list_shop);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));

        for (int i = 0; i < cloth.length; i++) {

            Shops shopsList = new Shops(cloth[i], wood[i], metal[i]);

            shops.add(shopsList);
        }

        ShopsAdapter adapter = new ShopsAdapter(shops);
        recyclerView.setAdapter(adapter);
    }
}

代码Class列表

public class Shops {
    String cloth, wood, metal;

    public Shops(String cloth, String wood, String metal) {
        this.cloth = cloth;
        this.wood = wood;
        this.metal = metal;
    }
}

代码Class适配器

public class ShopsAdapter extends RecyclerView.Adapter<ShopsAdapter.ShopsHolder> {

    private List<Shops> shopsList;

    public ShopsAdapter(List<Shops> shops) {
        this.shopsList = shops;
    }

    @Override
    public ShopsHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        View row = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.template_recycler_view, viewGroup, false);
        ShopsHolder holder = new ShopsHolder(row);
        return holder;
    }

    @Override
    public void onBindViewHolder(ShopsHolder holder, int i) {

        Shops shops = shopsList.get(i);
        holder.cloth.setText(shops.cloth);
        holder.wood.setText(shops.wood);
        holder.metal.setText(shops.metal);

    }

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

    class ShopsHolder extends RecyclerView.ViewHolder {
        private TextView cloth, wood, metal;

        public ShopsHolder(View itemView) {
            super(itemView);
            cloth = itemView.findViewById(R.id.cloth);
            wood = itemView.findViewById(R.id.wood);
            metal = itemView.findViewById(R.id.metal);
        }
    }
}

如果你需要XML代码，我会在另一个回复里放。

Answer 1

谢谢。经过反复实验。我能够得出一个结果。它正在使用 For loob 在你里面 addItem 所以

  public void addItem() {

        String[] cloth = {"Silk", "Cotton", "Linen"};
        String[] wood = {"Sandal", "Jawi", "Pine"};
        String[] metal = {"Window", "door", "roof"};

        RecyclerView recyclerView = findViewById(R.id.list_shop);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));

        for (int i = 0; i < cloth.length; i++) {

            Shops shopsList = new Shops(cloth[i], wood[i], metal[i]);

            shops.add(shopsList);

        }

        ShopsAdapter adapter = new ShopsAdapter(shops);
        recyclerView.setAdapter(adapter);

    // From here begins the solution code
        for (int i = 0; i < cloth.length; i++) {

            String clothMy = shops.get(i).cloth;
            String woodMy = shops.get(i).wood;
            String metalMy = shops.get(i).metal;

            Log.i("TAG",clothMy);
            Log.i("TAG",woodMy);
            Log.i("TAG",metalMy);

        }
    // Here ends the solution code

    }

Answer 2

像这样使用 getters() 和 setters() 创建模型/POJO class

public class Shops {

    private String cloth;
    private String wood;
    private String metal;

    public Shops(String cloth, String wood, String metal) {
        this.cloth = cloth;
        this.wood = wood;
        this.metal = metal;
    }

    public String getCloth() {
        return cloth;
    }

    public void setCloth(String cloth) {
        this.cloth = cloth;
    }

    public String getWood() {
        return wood;
    }

    public void setWood(String wood) {
        this.wood = wood;
    }

    public String getMetal() {
        return metal;
    }

    public void setMetal(String metal) {
        this.metal = metal;
    }
}

现在全局声明 ArrayList 并向其添加项目。当您单击按钮时，只需使用索引号访问它们。你可以运行一个 for 循环。

public class MainActivity extends AppCompatActivity {

private  List<Shops> shops;

protected void onCreate(Bundle savedInstanceState) {
    setContentView(R.layout.activity_main);
    super.onCreate(savedInstanceState);
    shops= new ArrayList<>();
    addItem();

    Button button = findViewById(R.id.get_item);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            /*
                I want when I press the button
                The items are called
             */
            shops.get(1).getCloth();
            shops.get(1).getWood();
            shops.get(1).getMetal();

            // do whatever you want with them

        }
    });

}

public void addItem() {


    String[] cloth = {"Silk", "Cotton", "Linen"};
    String[] wood = {"Sandal", "Jawi", "Pine"};
    String[] metal = {"Window", "door", "roof"};

    RecyclerView recyclerView = findViewById(R.id.list_shop);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));

    for (int i = 0; i < cloth.length; i++) {

        Shops shopsList = new Shops(cloth[i], wood[i], metal[i]);

        shops.add(shopsList);
    }

Answer 3

您的代码方式似乎可以满足您的需要，但我认为这不是一个很好的方式。与其在项目的某个位置创建一个 public 列表来缓存你想要的数据，不如让这个列表在你的适配器中私有，并通过添加一个 getItem(int pos) 通过适配器获取你想要的数据return item 通过你传递给它的 'pos' 参数，这样更安全，更专业。解决问题的方法有很多种，但哪种方法最好...

从 RecyclerView 检索数据

Retrieve data from RecyclerView

android

get

adapter

android-recyclerview