黄油刀是JakeWharton开源的一款Android视图字段方法绑定快速注解框架。可以不用findById，setOnclick等。大大提高开发效率。

依赖

compile 'com.jakewharton:butterknife:10.1.0'
annotationProcessor 'com.jakewharton:butterknife-compiler:10.1.0'

Butterknife基本使用

在Activity中绑定

public class MainActivity extends AppCompatActivity {

    @BindView(R.id.btn1) Button button1;

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

在fragment中绑定

public class BlankFragment extends Fragment {

    private BlankViewModel mViewModel;

    public static BlankFragment newInstance() {
        return new BlankFragment();
    }
    
    private Unbinder unbinder;
    @BindView(R.id.txt1)
    TextView textView;

    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container,
                             @Nullable Bundle savedInstanceState) {
        View root = inflater.inflate(R.layout.blank_fragment, container, false);
        unbinder = ButterKnife.bind(this,root);      //绑定视图
        
        return root;
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        mViewModel = new ViewModelProvider(this).get(BlankViewModel.class);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        unbinder.unbind();          //视图销毁需解绑
    }
}

Butterknife具体使用

单个组件id绑定：

@BindView(R.id.txt1)
    TextView textView;

点击事件：

@OnClick(R.id.btn1)
    public void btn1(){
        
    }

多组件同一点击事件

@OnClick({R.id.btn2,R.id.btn3,R.id.btn4})
    public void btn2(View view){
        
        }
    }

多组件多点击事件

@OnClick({R.id.btn2,R.id.btn3,R.id.btn4})
    public void btn2(View view){
        switch (view.getId()){
            case R.id.btn2:
                Toast.makeText(MainActivity.this,"btn2",Toast.LENGTH_SHORT).show();
                break;
            case R.id.btn3:
                Toast.makeText(MainActivity.this,"btn3",Toast.LENGTH_SHORT).show();
                break;
            case R.id.btn4:
                Toast.makeText(MainActivity.this,"btn4",Toast.LENGTH_SHORT).show();
                break;
        }
    }

列表组件的item点击事件

@OnItemClick({R.id.listView})
    public void test(int position){
        Toast.makeText(MainActivity.this,"position:"+position,Toast.LENGTH_SHORT).show();
    }