Android Service扩展了ResultReceiver for IntentService,如何实现CREATOR？

Question

我的应用程序依赖Service于在后台与外部硬件保持同步的应用程序.因为服务在主线程上运行,所以它使用IntentService异步执行任何繁重的工作.以下是解释控制流的代码的最小化示例:

public class MyService extends Service {
  private final Handler handler = new Handler();

  void someMethodDoesCallBarAsynchronously(){
    Intent i = new Intent(this, MyIntentService.class);
    i.putAction(ACTION_FOO);
    i.putExtra(EXTRA_RECEIVER, new MyResultReceiver(handler));
    startService(toGetScannerStatus);
  }

  void receivedFooResult(String bar){
    //...
  }

  public class MyResultReceiver extends ResultReceiver{

    public MyResultReceiver(Handler handler){
      super(handler);
    }

    @Override
    protected void onReceiveResult(int resultCode, Bundle resultData) {
      super.onReceiveResult(resultCode, resultData);

      switch(resultCode){
        case RESULT_CODE_FOO:
          receivedFooResult(resultData.getString(FOO_RESULT));
        break;
      }
    }
  }
}

public class MyIntentService extends IntentService {

  public MyIntentService(){super("MyIntentService");}

  @Override
  protected void onHandleIntent(Intent intent) {
    switch (intent.getAction()) {
      case ACTION_FOO:
        ResultReceiver receiver = intent.getParcelableExtra(EXTRA_RECEIVER);
        Bundle bundle = new Bundle()
        bundle.putString(FOO_RESULT, foo());
        receiver.send(RESULT_CODE_FOO, b);
      break;
  }
}

现在,经过半年和一些更新,Android Studio抱怨MyResultReceiver 实现Parcelable但不提供CREATOR字段.问题一,MyResultReceiver是一个内部类,所以我必须把它放到一个自己的类中.我无法创建它,static因为它必须包含对MyService的引用.这仍然很容易:

public class MyService extends Service {
  private final Handler handler = new Handler();

  void someMethodDoesCallBarAsynchronously(){
    Intent i = new Intent(this, MyIntentService.class);
    i.putAction(ACTION_FOO);
    i.putExtra(EXTRA_RECEIVER, new MyResultReceiver(this, handler));
    startService(toGetScannerStatus);
  }

  void receivedFooResult(String bar){
    //...
  }
}

public class MyResultReceiver extends ResultReceiver{
  private final MyService myService;

  public MyResultReceiver(MyService s, Handler handler){
    super(handler);
    this.myService = myService;
  }

  @Override
  protected void onReceiveResult(int resultCode, Bundle resultData) {
    super.onReceiveResult(resultCode, resultData);

    switch(resultCode){
      case RESULT_CODE_FOO:
        myService.receivedFooResult(resultData.getString(FOO_RESULT));
      break;
    }
  }
}

现在我可以添加一个公共静态字段.但是如何正确实现CREATOR？

public class MyResultReceiver extends ResultReceiver {

  public static final Parcelable.Creator<MyResultReceiver> CREATOR
    = new Parcelable.Creator<MyResultReceiver>() {
        public MyResultReceiver[] newArray(int size) {
          return new MyResultReceiver[size];
        }
        public MyResultReceiver createFromParcel(Parcel in) {
          // ???
        }
      };

如果你想:为什么这有必要？它将用于什么？

Answer 1

你当前的架构太复杂了:你可以很容易地做到这一点,Service但是当你遇到问题时,这取决于你:你不需要创建任何CREATOR你得到的是一个lint警告,只需添加SuppressLint注释像这样:

@SuppressLint("ParcelCreator")
public class MyResultReceiver extends ResultReceiver {