现在，安卓开发者用RecyclerView替代了以前的ListView或GridView。RecyclerView控件是更高级和灵活的ListView版本。这个控件是显示大数据集的容器，只维持有限数量的view就可以高效地滚动。
遗憾的是，不像之前ListView那样，Google并没有给我们提供一个默认的Recycler View Adapter类来继承。我首先将讨论Recycer View Adapter，它可以轻松的将对象列表绑定到你的RecyclerView上。
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import android.support.v7.widget.RecyclerView; import java.util.ArrayList; import java.util.List; public abstract class RecyclerViewArrayAdapter<T, VH extends RecyclerView.ViewHolder> extends RecyclerView.Adapter<VH> { private final List<T> items; public void bindData(final List<T> items) { this.items = items; this.notifyDataSetChanged(); } public final T getItem(final int position) { return this.items.get(position); } public List<T> getItems() { return items; } @Override public int getItemCount() { return this.items != null ? this.items.size() : 0; } @Override public final void onBindViewHolder(final VH holder, final int position) { final T item = this.getItem(position); this.onBindViewHolder(holder, item); } public abstract void onBindViewHolder(final VH holder, final T item); } |
这个类不难理解，也不包含大量的逻辑，而且它可以避免重复实现包含一个简单列表的Adapter类。
下面代码中你可以找到一个简单的Adapter，这个Adapter用来向一个RecyclerView中显示搜索结果。
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import android.content.Context; import android.support.v7.widget.RecyclerView; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.TextView; import butterknife.Bind; import butterknife.ButterKnife; public class SearchResultsAdapter extends RecyclerViewArrayAdapter<SearchResult, SearchResultsAdapter.SearchResultViewHolder> implements View.OnClickListener { private final LayoutInflater layoutInflater; private OnItemClickListener onItemClickListener; public SearchResultsAdapter(final Context context) { super(); this.layoutInflater = LayoutInflater.from(context); } public void setOnItemClickListener(final OnItemClickListener onItemClickListener) { this.onItemClickListener = onItemClickListener; } @Override public SearchResultViewHolder onCreateViewHolder(final ViewGroup parent, final int viewType) { final View view = this.layoutInflater.inflate(R.layout.listitem_search, parent, false); view.setOnClickListener(this); return new SearchResultViewHolder(view); } @Override public void onBindViewHolder(final SearchResultViewHolder holder, final SearchResult item) { holder.bindData(item); } /* * View.OnClickListener */ @Override public void onClick(final View view) { if (this.onItemClickListener != null) { final RecyclerView recyclerView = (RecyclerView) view.getParent(); final int position = recyclerView.getChildLayoutPosition(view); if (position != RecyclerView.NO_POSITION) { final SearchResult item = this.getItem(position); this.onItemClickListener.onItemClicked(item); } } } public static class SearchResultViewHolder extends RecyclerView.ViewHolder { @Bind(R.id.textview_name) TextView textViewName; public SearchResultViewHolder(final View itemView) { super(itemView); ButterKnife.bind(this, itemView); } public void bindData(final SearchResult item) { this.textViewName.setText(item.getName()); } } public interface OnItemClickListener { void onItemClicked(SearchResult item); } } |
为adapter绑定数据：
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final List<SearchResult> items = this.getSearchResults(); this.adapter.bindData(items); |
