Material Design - RecyclerView

根據 Android 官方的說法
RecyclerView 是比較先進而靈活的 ListView

RecyclerView 除了要使用 RecyclerView.Adapter 之外還必須指定一個 RecyclerView.LayoutManager

內建的 LayoutManager 有以下三種：
LinearLayoutManager (垂直或水平捲動的 List)
GridLayoutManager
StaggeredGridLayoutManager (交錯的 Grid)

另外 RecyclerView 對 item 的增加與移除有預設動畫
要自訂動畫的話必須繼承自 RecyclerView.ItemAnimator
再透過 RecyclerView.setItemAnimator() 指定

RecyclerView 在 layout xml 是長這樣

接下來看看 code 要怎麼用

public class MyActivity extends Activity {
    private RecyclerView mRecyclerView;
    private RecyclerView.Adapter mAdapter;
    private RecyclerView.LayoutManager mLayoutManager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.my_activity);
        mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);

        //如果內容的改變不會改變 RecyclerView 的 layout size, 這可以增進效能
        mRecyclerView.setHasFixedSize(true);

        mLayoutManager = new LinearLayoutManager(this);
        mRecyclerView.setLayoutManager(mLayoutManager);

        // specify an adapter (see also next example)
        mAdapter = new MyAdapter(myDataset);
        mRecyclerView.setAdapter(mAdapter);
    }
    ...省略
}

繼承 RecyclerView.Adapter 的實作範例

public class MyAdapter extends RecyclerView.Adapter {

    private String[] mDataset;

    // 繼承 RecyclerView.ViewHolder 的 ViewHolder 
    public static class ViewHolder extends RecyclerView.ViewHolder {
        // each data item is just a string in this case
        public TextView mTextView;
        public ViewHolder(TextView v) {
            super(v);
            mTextView = v;
        }
    }

    // 透過 constructor 傳入 dataset
    public MyAdapter(String[] myDataset) {
        mDataset = myDataset;
    }

    // 在 onCreateViewHolder 將 item view 給 inflate
    @Override
    public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View v = LayoutInflater.from(parent.getContext())
                               .inflate(R.layout.my_text_view, parent, false);

        // 調整 view 的 size, margins, paddings 及其他 layout parameters
        ...省略

        ViewHolder vh = new ViewHolder(v);
        return vh;
    }

    // 在 onBindViewHolder 將 item view 的內容(依照 position )做更換
    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        holder.mTextView.setText(mDataset[position]);
    }

    @Override
    public int getItemCount() {
        return mDataset.length;
    }
}

相關資料：
Creating Lists and Cards
Android develop 官方範例 - RecyclerView