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

  // ...

}

public class FancyFragment extends Fragment {

    @BindView(R.id.button1)

    Button button1;

    @BindView(R.id.button2)

    Button button2;

    @Override

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fancy_fragment, container, false);

        ButterKnife.bind(this, view);

        // TODO Use fields...

        return view;

    }

}

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);

        }

    }

}

ButterKnife.bind的调用可以被放在任何你想调用findViewById的地方。

提供的其他绑定API:

• 使用Activity作为跟布局在任意对象中进行绑定。如果你使用了类似MVC的编程模式，你可以对controller使用它的Activity用ButterKnife.bind(this, activity)进行绑定。

• 使用ButterKnife.bind(this)绑定一个布局的子布局。如果你在布局中使用了<merge>标签并且在自定义的控件构造时inflate这个布局，你可以在inflate之后立即调用它。或者，你可以在onFinishInflate()回调中使用它。

View 列表

你可以一次性将多个views绑定到一个List或数组中：

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

List<EditText> nameViews;

apply函数，该函数一次性在列表中的所有View上执行一个动作：

ButterKnife.apply(nameViews, DISABLE);

ButterKnife.apply(nameViews, ENABLED, false);

Action和Setter接口能够让你指定一些简单的动作：

static final ButterKnife.Action<View> DISABLE = new ButterKnife.Action<View>() {

    @Override

    public void apply(View view, int index) {

        view.setEnabled(false);

    }

};

static final ButterKnife.Setter<View, Boolean> ENABLED = new ButterKnife.Setter<View, Boolean>() {

    @Override

    public void set(View view, Boolean value, int index) {

        view.setEnabled(value);

    }

};

Android中的Property属性也可以使用apply方法进行设置：

ButterKnife.apply(nameViews, View.ALPHA, 0.0f);

监听器绑定

使用本框架，监听器能够自动的绑定到特定的执行方法上：

@OnClick(R.id.submit)

public void submit(View view) {

  // TODO submit data to server...

}

而监听器方法的参数都时可选的：

@OnClick(R.id.submit)

public void submit() {

    // TODO submit data to server...

}

指定一个特定的类型，Butter Knife也能识别：

@OnClick(R.id.submit)

public void sayHi(Button button) {

    button.setText("Hello!");

}

可以指定多个View ID到一个方法上，这样，这个方法就成为了这些View的共同事件处理。

@OnClick({ R.id.door1, R.id.door2, R.id.door3 })

public void pickDoor(DoorView door) {

    if (door.hasPrizeBehind()) {

        Toast.makeText(this, "You win!", LENGTH_SHORT).show();

    } else {

        Toast.makeText(this, "Try again", LENGTH_SHORT).show();

    }

}

自定义View时，绑定事件监听不需要指定ID

public class FancyButton extends Button {

    @OnClick

    public void onClick() {

        // TODO do something!

    }

}

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();

    }

}

@Nullable

@BindView(R.id.might_not_be_there)

TextView mightNotBeThere;

@Optional

@OnClick(R.id.maybe_missing)

void onMaybeMissingClicked() {

    // TODO ...

}

@OnItemSelected(R.id.list_view)

void onItemSelected(int position) {

    // TODO ...

}

@OnItemSelected(value = R.id.maybe_missing, callback = NOTHING_SELECTED)

void onNothingSelected() {

    // TODO ...

}

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);