NestedScrollView 内的 RecyclerView 导致 RecyclerView 膨胀所有元素

NestedScrollView 是一个功能强大的 Android 支持库，它可以提供滚动功能，并且可以包含其他可滚动的视图组件。其中，最常用的就是将 RecyclerView 放在 NestedScrollView 中实现滚动效果。然而，这种做法有时会导致 RecyclerView 中的元素全部加载，从而导致内存膨胀的问题。

xml
    android:layout_width="match_parent"
    android:layout_height="match_parent">
            android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">
                    android:id="@+id/recyclerViewA"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />
                    android:id="@+id/recyclerViewB"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />
    

java
// 创建数据源
List dataA = new ArrayList<>();
List dataB = new ArrayList<>();
// 添加数据
for (int i = 0; i < 100; i++) {
    dataA.add("Item A " + i);
    dataB.add("Item B " + i);
}
// 创建 Adapter
RecyclerView.Adapter adapterA = new RecyclerViewAdapter(dataA);
RecyclerView.Adapter adapterB = new RecyclerViewAdapter(dataB);
// 设置 Adapter
RecyclerView recyclerViewA = findViewById(R.id.recyclerViewA);
recyclerViewA.setLayoutManager(new LinearLayoutManager(this));
recyclerViewA.setAdapter(adapterA);
RecyclerView recyclerViewB = findViewById(R.id.recyclerViewB);
recyclerViewB.setLayoutManager(new LinearLayoutManager(this));
recyclerViewB.setAdapter(adapterB);

xml
    android:layout_width="match_parent"
    android:layout_height="match_parent">
            android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

java
// 创建数据源
List> data = new ArrayList<>();
// 添加数据
for (int i = 0; i < 10; i++) {
    List pageData = new ArrayList<>();
    for (int j = 0; j < 10; j++) {
        pageData.add("Item " + (i * 10 + j));
    }
    data.add(pageData);
}
// 创建 Adapter
RecyclerView.Adapter adapter = new NestedRecyclerViewAdapter(data);
// 设置 Adapter
RecyclerView recyclerView = findViewById(R.id.recyclerView);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setAdapter(adapter);

java
public class NestedRecyclerViewAdapter extends RecyclerView.Adapter {
    private List> mData;
    public NestedRecyclerViewAdapter(List> data) {
        mData = data;
    }
    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_nested_recyclerview, parent, false);
        return new ViewHolder(view);
    }
    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        List pageData = mData.get(position);
        RecyclerView.Adapter adapter = new RecyclerViewAdapter(pageData);
        holder.recyclerView.setLayoutManager(new LinearLayoutManager(holder.itemView.getContext()));
        holder.recyclerView.setAdapter(adapter);
    }
    @Override
    public int getItemCount() {
        return mData.size();
    }
    public static class ViewHolder extends RecyclerView.ViewHolder {
        RecyclerView recyclerView;
        public ViewHolder(View itemView) {
            super(itemView);
            recyclerView = itemView.findViewById(R.id.recyclerView);
        }
    }
}

java
public class DataItem {
    private String content;
    private int page;
    public DataItem(String content, int page) {
        this.content = content;
        this.page = page;
    }
    public String getContent() {
        return content;
    }
    public int getPage() {
        return page;
    }
}
// 创建数据源
List data = new ArrayList<>();
// 添加数据
for (int i = 0; i < 100; i++) {
    int page = i / 10 + 1;
    data.add(new DataItem("Item " + i, page));
}

java
@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
    List pageData = new ArrayList<>();
    for (DataItem item : mData) {
        if (item.getPage() == position + 1) {
            pageData.add(item.getContent());
        }
    }
    RecyclerView.Adapter adapter = new RecyclerViewAdapter(pageData);
    holder.recyclerView.setLayoutManager(new LinearLayoutManager(holder.itemView.getContext()));
    holder.recyclerView.setAdapter(adapter);
}

java
recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
    @Override
    public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
        super.onScrolled(recyclerView, dx, dy);
        LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
        int totalItemCount = layoutManager.getItemCount();
        int lastVisibleItemPosition = layoutManager.findLastVisibleItemPosition();
        if (lastVisibleItemPosition == totalItemCount - 1) {
            // 加载下一页的数据
            int nextPage = mData.get(totalItemCount - 1).getPage() + 1;
            for (int i = 0; i < 10; i++) {
                int index = (nextPage - 1) * 10 + i;
                mData.add(new DataItem("Item " + index, nextPage));
            }
            adapter.notifyDataSetChanged();
        }
    }
});