高效复用：RecyclerView Item中嵌套列表时的优化技巧

**高效复用：RecyclerView Item中嵌套列表时的优化技巧**

在Android开发中，使用RecyclerView来展示数据是非常常见的。然而，当我们需要在一个Item中嵌套另一个列表时，性能问题就变得更加明显。这篇文章将分享一些高效复用的技巧和实践经验，以帮助你优化你的RecyclerView Item中嵌套列表的性能。

**1. 使用ViewHolder**

首先，我们需要了解ViewHolder的概念。ViewHolder是一种缓存Item布局中的View的机制，它可以避免每次绘制Item时都重新创建这些View，从而提高性能。

javapublic class MyAdapter extends RecyclerView.Adapter {
 @Override public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
 View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_layout, parent, false);
 return new ViewHolder(view);
 }

 @Override public void onBindViewHolder(ViewHolder holder, int position) {
 // ...
 }

 public class ViewHolder extends RecyclerView.ViewHolder {
 public TextView textView;
 public RecyclerView recyclerView;

 public ViewHolder(View itemView) {
 super(itemView);
 textView = (TextView) itemView.findViewById(R.id.text_view);
 recyclerView = (RecyclerView) itemView.findViewById(R.id.recycler_view);
 }
 }
}

javapublic class MyAdapter extends RecyclerView.Adapter {
 private List mData;

 public void updateData(List data) {
 mData = data;
 notifyDataSetChanged();
 }

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

 @Override public void onBindViewHolder(ViewHolder holder, int position) {
 ItemData data = mData.get(position);
 // ...
 }
}

javapublic class MyAdapter extends RecyclerView.Adapter {
 private List mData;

 public void updateData(List data) {
 DiffUtil.calculateDiff(new ItemDiffCallback(mData, data), false);
 mData = data;
 notifyDataSetChanged();
 }

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

 @Override public void onBindViewHolder(ViewHolder holder, int position) {
 ItemData data = mData.get(position);
 // ...
 }
}

public class ItemDiffCallback extends DiffUtil.Callback {
 private List mOldList;
 private List mNewList;

 public ItemDiffCallback(List oldList, List newList) {
 mOldList = oldList;
 mNewList = newList;
 }

 @Override public int getOldListSize() {
 return mOldList.size();
 }

 @Override public int getNewListSize() {
 return mNewList.size();
 }

 @Override public boolean areItemsTheSame(int oldItemPosition, int newItemPosition) {
 // ...
 }
}

javapublic class MyAdapter extends RecyclerView.Adapter {
 private List mData;
 private Map> mCache;

 public void updateData(List data) {
 mData = data;
 mCache.clear();
 notifyDataSetChanged();
 }

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

 @Override public void onBindViewHolder(ViewHolder holder, int position) {
 ItemData data = mData.get(position);
 // ...
 }
}

javapublic class MyAdapter extends RecyclerView.Adapter {
 private List mData;
 private ExecutorService mThreadPool;

 public void updateData(List data) {
 mData = data;
 mThreadPool.execute(new Runnable() {
 @Override public void run() {
 notifyDataSetChanged();
 }
 });
 }

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

 @Override public void onBindViewHolder(ViewHolder holder, int position) {
 ItemData data = mData.get(position);
 // ...
 }
}