Recyclerview Databinding 코드 예제

안녕하세요. 삐질삐질 개발하는 개발자 삐질입니다.

오늘은 MVVM과 Databinding을 이용해  Recyclerview를 사용 하는 방법에 대해 알아보고자 합니다.

데이터 바인딩을 하기 위해서는 gradle에 추가해야 할 옵션이 있습니다.

https://ppizil.tistory.com/26 이 글부터 읽고 봐주세요 ~~~~ 

1. MainActivity.java 
   

public class MainActivity extends AppCompatActivity {

    private ActivityMainBinding binding;

    private MemoViewModel viewModel;

    @Override

    protected void onCreate(@Nullable Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        binding = DataBindingUtil.setContentView(this, R.layout.activity_main);

        init();

    }

    public void init() {

        viewModel = new MemoViewModel();

        viewModel.onCreate();

        binding.setViewmodel(viewModel);

        binding.setLifecycleOwner(this);

    }

}

2. MemoViewModel.java

public class MemoViewModel {

    private List<Memo> items;

    private RecyclerAdapter adapter;

    public MemoViewModel() {

        if (items == null) {

            items = new ArrayList<>();

        }

        if (adapter == null) {

            adapter = new RecyclerAdapter(this);

        }

        testLogic();

    }

    public void testLogic() {

        for (int i = 0; i < 30; i++) {

            Memo memo = new Memo();

            memo.setId(i);

            memo.setMemoContext("테스트 메몸입니다. " + i);

            memo.setTitle(i + "번째 메모 제목입니다.");

            items.add(memo);

        }

    }

    public void onCreate() {

        adapter.notifyDataSetChanged();

    }

    public void onResume() {

    }

    public RecyclerAdapter getAdapter() {

        return adapter;

    }

    public List<Memo> getItems() {

        return items;

    }

    public String getTitle(int pos) {

        return items.get(pos).getTitle();

    }

    public String getContents(int pos) {

        return items.get(pos).getMemoContext();

    }

}

3. RecyclerAdapter.java

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

    private MemoViewModel viewModel;

    public RecyclerAdapter(MemoViewModel viewModel) {

        this.viewModel = viewModel;

    }

    @NonNull

    @Override

    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

        ItemMemoBinding binding = ItemMemoBinding.inflate(LayoutInflater.from(parent.getContext()), parent, false);

        return new ItemViewHolder(binding);

    }

    @Override

    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {

        if (holder instanceof ItemViewHolder) {

            ((ItemViewHolder) holder).bind(viewModel, position);

        }

    }

    @Override

    public int getItemCount() {

        return viewModel.getItems() == null ? 0 : viewModel.getItems().size();

    }

    public static class ItemViewHolder extends RecyclerView.ViewHolder {

        private ItemMemoBinding binding;

        public ItemViewHolder(ItemMemoBinding binding) {

            super(binding.getRoot());

            this.binding = binding;

        }

        public void bind(MemoViewModel viewModel, int pos) {

            binding.setViewmodel(viewModel);

            binding.setPos(pos);

            binding.executePendingBindings();

        }

    }

}

4. Memo.java

public class Memo {

    int id;

    String title;

    String memoContext;

    public String getTitle() {

        return title;

    }

    public void setTitle(String title) {

        this.title = title;

    }

    public String getMemoContext() {

        return memoContext;

    }

    public void setMemoContext(String memoContext) {

        this.memoContext = memoContext;

    }

    public int getId() {

        return id;

    }

    public void setId(int id) {

        this.id = id;

    }

}

5. CustomAdapter.java

public class CustomAdapter {

    @BindingAdapter("bind:verAdapter")

    public static void verAdapter(RecyclerView recyclerView, RecyclerView.Adapter<?> adapter) {

        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(recyclerView.getContext());

        linearLayoutManager.setOrientation(RecyclerView.VERTICAL);

        recyclerView.setLayoutManager(linearLayoutManager);

        recyclerView.setAdapter(adapter);

    }

}

6. Activity_main.xml

<?xml version="1.0" encoding="utf-8"?>

<layout xmlns:bind="http://schemas.android.com/apk/res-auto">

    <data>

        <variable

            name="viewmodel"

            type="com.ppizil.recyclerviewtest.MemoViewModel" />

    </data>

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

        android:layout_width="match_parent"

        android:layout_height="match_parent"

        android:orientation="vertical">

        <androidx.recyclerview.widget.RecyclerView

            android:id="@+id/recyclerview"

            android:layout_width="match_parent"

            android:layout_height="match_parent"

            bind:verAdapter="@{viewmodel.getAdapter()}"></androidx.recyclerview.widget.RecyclerView>

    </LinearLayout>

</layout>

8. item_memo.xml

<?xml version="1.0" encoding="utf-8"?>

<layout>

    <data>

        <variable

            name="viewmodel"

            type="com.ppizil.recyclerviewtest.MemoViewModel" />

        <variable

            name="pos"

            type="Integer" />

    </data>

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:orientation="horizontal"

        android:padding="15dp">

        <TextView

            android:id="@+id/title"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:text="@{viewmodel.getTitle(pos)}"

            android:textSize="14dp" />

        <TextView

            android:id="@+id/contents"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:layout_marginStart="8dp"

            android:text="@{viewmodel.getContents(pos)}"

            android:textColor="#000000"

            android:textSize="18dp" />

    </LinearLayout>

</layout>

안드로이드 초보 개발자를 위해 아래와 같은 카카오 오픈톡을 운영 중입니다. 

https://open.kakao.com/o/gn4xqQ6