Android碎碎念 -- ButterKnife注解的使用

引用形式：

Maven

<dependency>
  <groupId>com.jakewharton</groupId>
  <artifactId>butterknife</artifactId>
  <version>7.0.1</version>
</dependency>

Gradle

compile 'com.jakewharton:butterknife:7.0.1'

使用方法：

Activity绑定示例

class ExampleActivity extends Activity {
  @Bind(R.id.title) TextView title;
  @Bind(R.id.subtitle) TextView subtitle;
  @Bind(R.id.footer) TextView footer;

  @Override public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.simple_activity);
    ButterKnife.bind(this);//绑定Activity
    // TODO Use fields...
  }
}

Non Activity绑定示例

public class FancyFragment extends Fragment {
  @Bind(R.id.button1) Button button1;
  @Bind(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;
  }
}

View Holder绑定示例

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 {
    @Bind(R.id.title) TextView name;
    @Bind(R.id.job_title) TextView jobTitle;

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

监听器示例

//监听器也可以自动配置进方法中：
@OnClick(R.id.submit)
public void submit(View view) {
  // TODO submit data to server...
}

//监听方法的所有参数可以被操作：
@OnClick(R.id.submit)
public void submit() {
  // TODO submit data to server...
}

//定义一个具体的类型并且它将会自动的被类型转换
@OnClick(R.id.submit)
public void sayHi(Button button) {
  button.setText("Hello!");
}

//对通用事件操作时在一个单独的绑定中声明多个ID
@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可以绑定在他们自己的监听器上并且不需要具体声明一个ID
public class FancyButton extends Button {
  @OnClick
  public void onClick() {
    // TODO do something!
  }
}

BINDING RESET

Fragment和Activity相比有不同的生命周期。当在一个Fragment的onCreateView中绑定的时候，需要在onDestoryView中设置Views为null。但是，Butter Knife 有一个 unbind 方法来自动的做这件事。

public class FancyFragment extends Fragment {
  @Bind(R.id.button1) Button button1;
  @Bind(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;
  }

  @Override public void onDestroyView() {
    super.onDestroyView();
    ButterKnife.unbind(this);//解除绑定
  }
}

参考地址：

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

Introduction：http://jakewharton.github.io/butterknife/

示例版本为7.0.0，早前版本使用上有一定差别。