안드로이드 BaseAdapter 예제

- android.widget.BaseAdapter 적용
- ViewHolder 방식 사용



1. BaseAdapter 구현
public class TextListAdapter extends BaseAdapter {
    private LayoutInflater inflater;

    static class Holder {

        private final TextView text;

        public Holder(View itemView) {
            this.text = itemView.findViewById(android.R.id.text1);
        }

        void bindData(String item) {
            text.setText(item);
        }
    }

    private final ArrayList<String> contentItems = new ArrayList<>();

    @Override
    public int getCount() {
        return contentItems == null ? 0 : contentItems.size();
    }

    @Override
    public String getItem(int position) {
        return contentItems != null && position < getCount() ? contentItems.get(position) : null;
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if (inflater == null)
            inflater = LayoutInflater.from(parent.getContext());

        Holder holder;
        if (convertView == null) {
            convertView = inflater.inflate(android.R.layout.simple_list_item_1, parent, false);
            holder = new Holder(convertView);
        } else {
            holder = (Holder) convertView.getTag();
        }

        holder.bindData(getItem(position));
        return convertView;
    }
}

- Holder 클래스(ViewHolder)를 View 태그에 넣어서 재활용한다.
- ListView 어뎁터 구현의 가장 기본이 되는 방식.




2. ListView 구현
public class TextListFragment extends Fragment {

    public TextListFragment() {
        // Required empty public constructor
    }

    public static TextListFragment newInstance() {
        TextListFragment fragment = new TextListFragment();
        Bundle args = new Bundle();
        fragment.setArguments(args);
        return fragment;
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        ArrayList<String> items = new ArrayList<>();
        items.add("Text Item 1");
        items.add("Text Item 2");
        items.add("Text Item 3");

        View view = inflater.inflate(R.layout.fragment_text_list, container, false);
        ListView listView = view.findViewById(R.id.listView);
        listView.setAdapter(new TextListAdapter(items));
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Object item = parent.getItemAtPosition(position);
                if (item instanceof String) {

                }
            }
        });
        return view;
    }
}


- AdapterView에서 아이템을 가져와 클릭이벤트에 해당하는 아이템을 불러온다.