Google Drive Android API中driveId.getResourceID（）的不可预测结果

Question

我怀疑这是一个定时/延迟问题，但不清楚是否有应用程序操作会强制刷新。“Drive.DriveAPI.RequestSync(GAC)”似乎没有影响。

Answer 1

更新(07/22/2015)
多亏了Steven Bazyl的迅速响应（见下面的评论），我终于有了一个使用完成事件的令人满意的解决方案。下面是两个简化的代码片段，在新创建的文件传播到驱动器时，它们将ResourceId传递到应用程序：

文件创建，添加更改订阅：

public class CreateEmptyFileActivity extends BaseDemoActivity {
  private static final String TAG = "_X_";

  @Override
  public void onConnected(Bundle connectionHint) {   super.onConnected(connectionHint);

    MetadataChangeSet meta = new MetadataChangeSet.Builder()
      .setTitle("EmptyFile.txt").setMimeType("text/plain")
      .build();

    Drive.DriveApi.getRootFolder(getGoogleApiClient())
      .createFile(getGoogleApiClient(), meta, null,
        new ExecutionOptions.Builder()
          .setNotifyOnCompletion(true)
          .build()
      )
      .setResultCallback(new ResultCallback<DriveFileResult>() {
        @Override
        public void onResult(DriveFileResult result) {
          if (result.getStatus().isSuccess()) {
            DriveId driveId = result.getDriveFile().getDriveId();
            Log.d(TAG, "Created a empty file: " + driveId);
            DriveFile file = Drive.DriveApi.getFile(getGoogleApiClient(), driveId);
            file.addChangeSubscription(getGoogleApiClient());
          }
        }
      });
  }
}

事件服务，捕获完成：

public class ChngeSvc extends DriveEventService {
  private static final String TAG = "_X_";

  @Override
  public void onCompletion(CompletionEvent event) {  super.onCompletion(event);
    DriveId driveId = event.getDriveId();
    Log.d(TAG, "onComplete: " + driveId.getResourceId());
    switch (event.getStatus()) {
      case CompletionEvent.STATUS_CONFLICT:  Log.d(TAG, "STATUS_CONFLICT"); event.dismiss(); break;
      case CompletionEvent.STATUS_FAILURE:   Log.d(TAG, "STATUS_FAILURE");  event.dismiss(); break;
      case CompletionEvent.STATUS_SUCCESS:   Log.d(TAG, "STATUS_SUCCESS "); event.dismiss(); break;
    }
  }
}

20:40:53.247﹕Created a empty file: DriveId:CAESABiiAiDGsfO61VMoAA==
20:40:54.305: onComplete, ResourceId: 0BxOS7mTBMR_bMHZRUjJ5NU1ZOWs

最初，我实现了Cheryl Simon的建议，并在新创建的文件上添加了一个ChangeListener，希望在文件传播时获得ResourceID。使用android-demos中的经典CreateEmptyFileActivity，我将以下测试代码拼凑在一起：

public class CreateEmptyFileActivity extends BaseDemoActivity {
  private static final String TAG = "CreateEmptyFileActivity";

  final private ChangeListener mChgeLstnr = new ChangeListener() {
    @Override
    public void onChange(ChangeEvent event) {
      Log.d(TAG, "event: " + event + " resId: " + event.getDriveId().getResourceId());
    }
  };


  @Override
  public void onConnected(Bundle connectionHint) {   super.onConnected(connectionHint);

    MetadataChangeSet meta = new MetadataChangeSet.Builder()
      .setTitle("EmptyFile.txt").setMimeType("text/plain")
      .build();

    Drive.DriveApi.getRootFolder(getGoogleApiClient())
      .createFile(getGoogleApiClient(), meta, null)
      .setResultCallback(new ResultCallback<DriveFileResult>() {
        @Override
        public void onResult(DriveFileResult result) {
          if (result.getStatus().isSuccess()) {
            DriveId driveId = result.getDriveFile().getDriveId();
            Log.d(TAG, "Created a empty file: " + driveId);
            Drive.DriveApi.getFile(getGoogleApiClient(), driveId).addChangeListener(getGoogleApiClient(), mChgeLstnr);
          }
        }
      });
  }
}

...一直在等着什么事情发生。文件在几秒钟内被愉快地上传到驱动器上，但没有onChange（）事件。10分钟，20分钟……我找不到任何方法让ChangeListener醒来。

所以我能想出的唯一的解决方案是轻推GDAA。因此，我实现了一个简单的处理程序--扑克，它在发生某些事情之前一直让元数据发痒：

public class CreateEmptyFileActivity extends BaseDemoActivity {
  private static final String TAG = "CreateEmptyFileActivity";

  final private ChangeListener mChgeLstnr = new ChangeListener() {
    @Override
    public void onChange(ChangeEvent event) {
      Log.d(TAG, "event: " + event + " resId: " + event.getDriveId().getResourceId());
    }
  };

  static DriveId driveId;
  private static final int ENOUGH = 4;    // nudge 4x,  1+2+3+4 = 10seconds
  private static int mWait = 1000;
  private int mCnt;
  private Handler mPoker;
  private final Runnable mPoke = new Runnable() { public void run() {
    if (mPoker != null && driveId != null && driveId.getResourceId() == null && (mCnt++ < ENOUGH)) {
      MetadataChangeSet meta = new MetadataChangeSet.Builder().build();
      Drive.DriveApi.getFile(getGoogleApiClient(), driveId).updateMetadata(getGoogleApiClient(), meta).setResultCallback(
        new ResultCallback<DriveResource.MetadataResult>() {
          @Override
          public void onResult(DriveResource.MetadataResult result) {
            if (result.getStatus().isSuccess() && result.getMetadata().getDriveId().getResourceId() != null)
              Log.d(TAG, "resId COOL " + result.getMetadata().getDriveId().getResourceId());
            else
              mPoker.postDelayed(mPoke, mWait *= 2);
          }
        }
      );
    } else {
      mPoker = null;
    }
  }};

  @Override
  public void onConnected(Bundle connectionHint) {   super.onConnected(connectionHint);

    MetadataChangeSet meta = new MetadataChangeSet.Builder()
      .setTitle("EmptyFile.txt").setMimeType("text/plain")
      .build();

    Drive.DriveApi.getRootFolder(getGoogleApiClient())
      .createFile(getGoogleApiClient(), meta, null)
      .setResultCallback(new ResultCallback<DriveFileResult>() {
        @Override
        public void onResult(DriveFileResult result) {
          if (result.getStatus().isSuccess()) {
            driveId = result.getDriveFile().getDriveId();
            Log.d(TAG, "Created a empty file: " + driveId);
            Drive.DriveApi.getFile(getGoogleApiClient(), driveId).addChangeListener(getGoogleApiClient(), mChgeLstnr);

            mCnt = 0;
            mPoker = new Handler();
            mPoker.postDelayed(mPoke, mWait);
          }
        }
      });
  }
}