如何实现RecyclerView嵌套及点击项跳转至带指定数据的RecyclerView（Java）

嘿，这个需求其实挺常见的，咱们一步步来实现：

1. 准备布局文件 #

首先，外层RecyclerView的每个item布局（比如item_outer.xml）里要嵌套内层RecyclerView：

<!-- item_outer.xml -->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="16dp">

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

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/inner_recycler"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"/>
</LinearLayout>

2. 编写内层RecyclerView的Adapter（带点击回调） #

内层Adapter需要定义点击接口，把选中的数据传递出去：

public class InnerAdapter extends RecyclerView.Adapter<InnerAdapter.InnerViewHolder> {
    private List<String> innerDataList;
    private OnInnerItemClickListener listener;

    // 定义点击回调接口
    public interface OnInnerItemClickListener {
        void onInnerItemClick(String data);
    }

    public InnerAdapter(List<String> innerDataList, OnInnerItemClickListener listener) {
        this.innerDataList = innerDataList;
        this.listener = listener;
    }

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

    @Override
    public void onBindViewHolder(@NonNull InnerViewHolder holder, int position) {
        String data = innerDataList.get(position);
        holder.tvInnerText.setText(data);

        // 设置点击事件
        holder.itemView.setOnClickListener(v -> {
            if (listener != null) {
                listener.onInnerItemClick(data);
            }
        });
    }

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

    static class InnerViewHolder extends RecyclerView.ViewHolder {
        TextView tvInnerText;

        public InnerViewHolder(@NonNull View itemView) {
            super(itemView);
            tvInnerText = itemView.findViewById(R.id.tv_inner_text);
        }
    }
}

3. 编写外层RecyclerView的Adapter #

外层Adapter需要初始化内层RecyclerView，并处理内层的点击回调，再传递给上层组件：

public class OuterAdapter extends RecyclerView.Adapter<OuterAdapter.OuterViewHolder> {
    private List<OuterItem> outerDataList;
    private OnInnerItemClickListener innerClickListener;

    // 外层数据实体类，包含标题和内层数据列表
    public static class OuterItem {
        public String title;
        public List<String> innerData;

        public OuterItem(String title, List<String> innerData) {
            this.title = title;
            this.innerData = innerData;
        }
    }

    // 对外暴露内层点击的回调
    public interface OnInnerItemClickListener {
        void onInnerItemClick(String data);
    }

    public OuterAdapter(List<OuterItem> outerDataList, OnInnerItemClickListener innerClickListener) {
        this.outerDataList = outerDataList;
        this.innerClickListener = innerClickListener;
    }

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

    @Override
    public void onBindViewHolder(@NonNull OuterViewHolder holder, int position) {
        OuterItem item = outerDataList.get(position);
        holder.tvOuterTitle.setText(item.title);

        // 初始化内层RecyclerView
        InnerAdapter innerAdapter = new InnerAdapter(item.innerData, innerClickListener);
        holder.innerRecycler.setLayoutManager(new LinearLayoutManager(holder.itemView.getContext()));
        holder.innerRecycler.setAdapter(innerAdapter);
    }

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

    static class OuterViewHolder extends RecyclerView.ViewHolder {
        TextView tvOuterTitle;
        RecyclerView innerRecycler;

        public OuterViewHolder(@NonNull View itemView) {
            super(itemView);
            tvOuterTitle = itemView.findViewById(R.id.tv_outer_title);
            innerRecycler = itemView.findViewById(R.id.inner_recycler);
        }
    }
}

4. 在Activity/Fragment中使用并获取选中数据 #

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        RecyclerView outerRecycler = findViewById(R.id.outer_recycler);
        outerRecycler.setLayoutManager(new LinearLayoutManager(this));

        // 构造测试数据
        List<OuterAdapter.OuterItem> outerData = new ArrayList<>();
        outerData.add(new OuterAdapter.OuterItem("分组1", Arrays.asList("子项1-1", "子项1-2", "子项1-3")));
        outerData.add(new OuterAdapter.OuterItem("分组2", Arrays.asList("子项2-1", "子项2-2")));

        // 设置外层Adapter，监听内层点击事件
        OuterAdapter outerAdapter = new OuterAdapter(outerData, data -> {
            // 这里就是你拿到的内层选中行的数据，可以做后续处理
            Toast.makeText(MainActivity.this, "选中了：" + data, Toast.LENGTH_SHORT).show();
        });
        outerRecycler.setAdapter(outerAdapter);
    }
}

这个需求也很清晰，咱们按以下步骤来：

1. 准备两个页面及布局 #

• 主页面（MainActivity）布局包含第一个RecyclerView；
• 详情页面（DetailActivity）布局包含第二个RecyclerView。

2. 第一个RecyclerView的Adapter（带点击回调） #

public class MainAdapter extends RecyclerView.Adapter<MainAdapter.MainViewHolder> {
    private List<MainItem> mainDataList;
    private OnItemClickListener listener;

    // 主页面数据实体，包含标题和对应详情页的数据集
    public static class MainItem {
        public String title;
        public List<String> detailData;

        public MainItem(String title, List<String> detailData) {
            this.title = title;
            this.detailData = detailData;
        }
    }

    public interface OnItemClickListener {
        void onItemClick(MainItem item);
    }

    public MainAdapter(List<MainItem> mainDataList, OnItemClickListener listener) {
        this.mainDataList = mainDataList;
        this.listener = listener;
    }

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

    @Override
    public void onBindViewHolder(@NonNull MainViewHolder holder, int position) {
        MainItem item = mainDataList.get(position);
        holder.tvTitle.setText(item.title);

        // 设置item点击事件
        holder.itemView.setOnClickListener(v -> {
            if (listener != null) {
                listener.onItemClick(item);
            }
        });
    }

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

    static class MainViewHolder extends RecyclerView.ViewHolder {
        TextView tvTitle;

        public MainViewHolder(@NonNull View itemView) {
            super(itemView);
            tvTitle = itemView.findViewById(R.id.tv_main_title);
        }
    }
}

3. 主页面处理点击跳转，传递数据 #

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        RecyclerView mainRecycler = findViewById(R.id.main_recycler);
        mainRecycler.setLayoutManager(new LinearLayoutManager(this));

        // 构造预设数据，每个主项对应一组详情数据
        List<MainAdapter.MainItem> mainData = new ArrayList<>();
        mainData.add(new MainAdapter.MainItem("商品分类1", Arrays.asList("商品A", "商品B", "商品C")));
        mainData.add(new MainAdapter.MainItem("商品分类2", Arrays.asList("商品D", "商品E")));

        MainAdapter adapter = new MainAdapter(mainData, item -> {
            // 跳转到详情页面，传递选中项的详情数据
            Intent intent = new Intent(MainActivity.this, DetailActivity.class);
            // 这里把数据序列化传递，自定义实体类建议实现Parcelable效率更高
            intent.putExtra("DETAIL_DATA", (Serializable) item.detailData);
            startActivity(intent);
        });
        mainRecycler.setAdapter(adapter);
    }
}

4. 详情页面接收数据并加载RecyclerView #

public class DetailActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_detail);

        RecyclerView detailRecycler = findViewById(R.id.detail_recycler);
        detailRecycler.setLayoutManager(new LinearLayoutManager(this));

        // 接收传递过来的数据
        List<String> detailData = (List<String>) getIntent().getSerializableExtra("DETAIL_DATA");

        // 设置详情页的Adapter，加载对应数据
        DetailAdapter detailAdapter = new DetailAdapter(detailData);
        detailRecycler.setAdapter(detailAdapter);
    }

    // 详情页的RecyclerView Adapter
    static class DetailAdapter extends RecyclerView.Adapter<DetailAdapter.DetailViewHolder> {
        private List<String> detailDataList;

        public DetailAdapter(List<String> detailDataList) {
            this.detailDataList = detailDataList;
        }

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

        @Override
        public void onBindViewHolder(@NonNull DetailViewHolder holder, int position) {
            holder.tvDetail.setText(detailDataList.get(position));
        }

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

        static class DetailViewHolder extends RecyclerView.ViewHolder {
            TextView tvDetail;

            public DetailViewHolder(@NonNull View itemView) {
                super(itemView);
                tvDetail = itemView.findViewById(R.id.tv_detail_text);
            }
        }
    }
}

内容的提问来源于stack exchange，提问作者MossXD