這次要介紹的RecyclerView可以說是ListView的改良版，相較於ListView，它較ListView更有彈性、容易客製化，且具官方說法，效能方面有很大的提升，在有了ListView的基礎後，設計RecyclerView也會理解較快。

首先，在gradle加入以下library dependency 後按下Sync Now
implementation 'com.android.support:appcompat-v7:23.4.0'
implementation 'com.android.support:design:23.4.0'
完成以後就可以開始RecyclerView設計了

XML

在XML插入RecyclerView元件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

接著設定RecyclerView中每一行要顯示的元件，開一個新的XML取名為list_content.xml，內容為下

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="60dp"
    android:orientation="horizontal">
        <TextView
            android:id="@+id/fileTitle"
            android:text="TextView"
            android:layout_width="match_parent"
            android:layout_height="60dp"
            android:layout_marginLeft="5dp"
            android:gravity="center_vertical|left" ></TextView>
</LinearLayout>

接下來開始定義Adapter，在右邊專案資料夾右鍵 -> New -> Java Class，創建一個Class，範例中命名為MyAdapter並繼承RecyclerView.Adapter<MyAdapter.ViewHolder>

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

    ArrayList<String> titleList;

    //帶入ArrayList作為資料
    public MyAdapter(ArrayList<String> titleList) {
        this.titleList = titleList;
    }

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

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        holder.fileTitle.setText(titleList.get(position));
    }

    //RecyclerView長度
    @Override
    public int getItemCount() {
        return titleList.size();
    }

    class ViewHolder extends RecyclerView.ViewHolder {
        public ImageView img;
        public TextView fileTitle;

        public ViewHolder(View holder) {
            super(holder);
            //綁定元件ID
            fileTitle = (TextView) holder.findViewById(R.id.fileTitle);
        }
    }
}

設定完Adapter就可開始撰寫MainActivity

public class MainActivity extends AppCompatActivity {

    MyAdapter adapter;
    RecyclerView recyclerView;
    ArrayList<String> titleList = new ArrayList();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        recyclerView = findViewById(R.id.recyclerView);

        //給titleList資料
        for(int i = 0;i<10;i++){
            titleList.add(String.valueOf(i));
        }

        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        recyclerView.addItemDecoration(new DividerItemDecoration(this,
        DividerItemDecoration.VERTICAL));
        adapter = new MyAdapter(titleList);
        recyclerView.setAdapter(adapter);
    }
}

成果