안드로이드 코딩을 좀 더 간단하게 "ButterKnife"

링크: https://github.com/JakeWharton/butterknife

ButterKnife는 Annotation기능을 이용하여 코딩을 쉽게할 수 있는 방법입니다.

※ Bind를 시켜야 사용 가능 (Kotlin과 비슷)

        
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class Example extends Activity {
  @Override public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.simple_activity);
	
    // Bind 하세요.
    ButterKnife.bind(this);
  }
}

 @BindView 를 이용하면 자동으로 ID 설정과 캐스트를 해줌

        
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// With ButterKnife
@BindView(R.id.title) TextView title;

@BindView(R.id.subtitle) TextView subtitle;

@BindView(R.id.footer) TextView footer;

@BindView(R.id.button1) Button button1;

// Original
subtitle= (TextView ) findViewById(R.id.subtitle);
...

ETC

        
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View view = LayoutInflater.from(context).inflate(R.layout.thing, null);
TextView firstName = ButterKnife.findById(view, R.id.first_name);
TextView lastName = ButterKnife.findById(view, R.id.last_name);
ImageView photo = ButterKnife.findById(view, R.id.photo);

Resource Binding

        
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class ExampleActivity extends Activity {
  @BindString(R.string.title) String title;
  @BindDrawable(R.drawable.graphic) Drawable graphic;
  @BindColor(R.color.red) int red; // int or ColorStateList field
  @BindDimen(R.dimen.spacer) Float spacer; // int (for pixel size) or float (for exact value) field
}

ListAdapter의 Viewholder 심플화

        
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public class MyAdapter extends BaseAdapter {
  @Override public View getView(int position, View view, ViewGroup parent) {
    ViewHolder holder;
    if (view != null) {
      holder = (ViewHolder) view.getTag();
    } else {
      view = inflater.inflate(R.layout.whatever, parent, false);
      holder = new ViewHolder(view);
      view.setTag(holder);
    }

    holder.name.setText("John Doe");
    // etc...

    return view;
  }

  static class ViewHolder {
    @BindView(R.id.title) TextView name;
    @BindView(R.id.job_title) TextView jobTitle;

    public ViewHolder(View view) {
      ButterKnife.bind(this, view);
    }
  }
}

List Array 형식도 심플화 가능

        
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@BindViews({ R.id.first_name, R.id.middle_name, R.id.last_name })
List nameViews;









Click 기능 심플 (void 이름 자유)



        
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@OnClick(R.id.submit) void submit() {
    // TODO call server...
  }





OnClick 예제








지원
OnClick, OnEditorAction, OnCheckedChanged, OnItemClick,
 OnItemSelected, OnLongClick, OnPageChange, OnTextChanged, OnTouch



더 많은 기능이 있지만 http://jakewharton.github.io/butterknife/ 를 직접 참고

※주의※ Fragment binding reset

        
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public class FancyFragment extends Fragment {
  @BindView(R.id.button1) Button button1;
  @BindView(R.id.button2) Button button2;
  private Unbinder unbinder;

  @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fancy_fragment, container, false);
    unbinder = ButterKnife.bind(this, view);
    // TODO Use fields...
    return view;
  }

  @Override public void onDestroyView() {
    super.onDestroyView();
    unbinder.unbind();
  }
}

개발자: JakeWharton


ButterKnife 사용을 위한 설정!


앱 build.gradle 에

dependencies {
  compile 'com.jakewharton:butterknife:8.7.0'
  annotationProcessor 'com.jakewharton:butterknife-compiler:8.7.0'
}

2015-04-07: ButterKnife 업데이트 대응 글 내용 변경 (InjectView -> FindView, inject -> bind)

2016-08-17: ButterKnife v8.2.1

2017-07-06: ButterKnife v8.6.0

2017-07-09: ButterKnife v8.7.0