RecyclerView 介绍 01

RecyclerView是Android support v7里面是一个自定义控件。用来显示大量数据集合。类似ListView和GridView这两个控件，RecyclerView同样可以实现，甚至更好。

以前我们在实现ListView和GridView的时候，都会定义一个ViewHolder用于优化UI性能【详见】，RecycleView的实现，已经是自带ViewHolder的实现。请看示例。

实现Adapter，定义每个Item的布局UI和数据。

public class MyRecyclerAdapter extends RecyclerView.Adapter<MyRecyclerAdapter.ViewHolder> {

private List<String> mDatas = new ArrayList<>(0);

public MyRecyclerAdapter(List<String> datas) {

if (datas != null) {

mDatas.addAll(datas);

}

}

public static final class ViewHolder extends RecyclerView.ViewHolder {

private final TextView textView;

private final Button button;

public ViewHolder(View itemView) {

super(itemView);

textView = (TextView) itemView.findViewById(R.id.item_text);

button = (Button) itemView.findViewById(R.id.item_button);

button.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

Toast.makeText(v.getContext(), String.valueOf(getPosition()), Toast.LENGTH_SHORT).show();

}

});

}

public TextView getTextView() {

return textView;

}

public Button getButton() {

return button;

}

}

@Override

public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item, null);

return new ViewHolder(view);

}

@Override

public void onBindViewHolder(ViewHolder holder, int position) {

holder.getButton().setText(String.valueOf(position));

holder.getTextView().setText(mDatas.get(position));

}

@Override

public int getItemCount() {

return mDatas.size();

}

}

初始化RecyclerView
设置Adapter和LayoutManager。LayoutManager定义了每个Item的排列形式。官方提供两种实现，LinearLayoutManager和GridLayoutManager，当然我们也可以根据需求，自己实现LayoutManager。

recyclerView = (RecyclerView) findViewById(R.id.recycler);

MyRecyclerAdapter adapter = new MyRecyclerAdapter(Datas.getDatas(1000));

RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false);

recyclerView.setLayoutManager(layoutManager);

recyclerView.setAdapter(adapter);

RecyclerView就是这么简单。

源码：GitHub