1. 项目结构

2. MainActivity

package com.example.myapplication;

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import com.example.myapplication.R;

import java.util.ArrayList;
import java.util.List;

public class SecondActivity extends AppCompatActivity {

    private RecyclerView recyclerView;
    private List<Item> itemList;

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

        itemList = generateItemList();

        recyclerView = findViewById(R.id.recyclerView);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        recyclerView.setAdapter(new MyAdapter(itemList));
    }

    private List<Item> generateItemList() {
        List<Item> list = new ArrayList<>();
        // 生成一级列表数据
        for (int i = 1; i <= 5; i++) {
            list.add(new Item("Item " + i, false)); // 将第二个参数设为false表示不展开
            // 生成二级列表数据
            for (int j = 1; j <= 3; j++) {
                list.add(new Item("Sub Item " + i + "-" + j, true)); // 将第二个参数设为true表示是二级列表项
            }
        }
        return list;
    }

    private static class Item {
        String name;
        boolean isSubItem;

        Item(String name, boolean isSubItem) {
            this.name = name;
            this.isSubItem = isSubItem;
        }
    }

    private static class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

        private List<Item> itemList;

        MyAdapter(List<Item> itemList) {
            this.itemList = itemList;
        }

        @NonNull
        @Override
        public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
            View view;
            if (viewType == 0) {
                view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_layout, parent, false);
            } else {
                view = LayoutInflater.from(parent.getContext()).inflate(R.layout.sub_item_layout, parent, false);
            }
            return new ItemViewHolder(view);
        }

        @Override
        public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
            Item item = itemList.get(position);
            if (item.isSubItem) {
                ((ItemViewHolder) holder).subItemName.setText(item.name);
            } else {
                ((ItemViewHolder) holder).itemName.setText(item.name);
            }
        }

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

        @Override
        public int getItemViewType(int position) {
            return itemList.get(position).isSubItem ? 1 : 0;
        }

        private static class ItemViewHolder extends RecyclerView.ViewHolder {
            TextView itemName;
            TextView subItemName;

            ItemViewHolder(@NonNull View itemView) {
                super(itemView);
                itemName = itemView.findViewById(R.id.tv_item_name);
                subItemName = itemView.findViewById(R.id.tv_sub_item_name);
            }
        }
    }
}

3. activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

4. item_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:padding="16dp"
    android:orientation="vertical">

    <TextView
        android:id="@+id/tv_item_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="18sp"
        android:textStyle="bold" />

</LinearLayout>

5. sub_item_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:padding="16dp"
    android:orientation="vertical"
    android:layout_marginStart="32dp"> <!-- 二级列表项缩进 -->

    <TextView
        android:id="@+id/tv_sub_item_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="16sp" />

</LinearLayout>