MainActivity 中的 BroadcastReceiver 不接收广播意图

Question

我是Android编程新手，所以我可能会犯非常愚蠢的错误。我正在编写一个简单的应用程序来收集活动数据。我有一个MainActivity和一个ActivityRecognizedService来查询谷歌的活动识别API。我正在尝试接收从ActivityRecognizedService到MainActivity的识别活动，以便以后可以定期将记录与我将收集的其他数据一起写入文件。问题是，我将用于在文件上写入数据的线程没有接收广播消息。这是该项目的MWE。

在： 活动识别服务.java

public class ActivityRecognizedService extends IntentService {
    public static final String LOCAL_BROADCAST_NAME = new String("API.ACTIVITY.BROADCAST_NAME");
    public ActivityRecognizedService() {
        super("ActivityRecognizedService");
    }
    public ActivityRecognizedService(String name) {
        super(name);
    }
    @Override
    protected void onHandleIntent(@Nullable Intent intent) {
        if (ActivityRecognitionResult.hasResult(intent)) {
            ActivityRecognitionResult activityRecognitionResult = ActivityRecognitionResult.extractResult(intent);
            Log.e("API.ACTIVITY.DETECTION", "Activity detected: " + activityRecognitionResult.getMostProbableActivity().toString());
            /* This DOES log the activity when detected */
            LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
        }
    }
}

在主活动中.java

public class MainActivity
        extends AppCompatActivity 
        implements GoogleApiClient.ConnectionCallbacks,
            GoogleApiClient.OnConnectionFailedListener {
    private ActivityRecognitionResult activityRecognitionResult;
    private GoogleApiClient googleApiClient;
    private BroadcastReceiver broadcastReceiver;
    @Override
    protected void onCreate(Bundle savedInstance) {
         super.onCreate(savedInstance);
         setContentView(R.layout.activity_main);
         /* check permissions, Google Play Services availabililty ... */
         googleApiClient = new GoogleApiClient.Builder(this);
                 .addApi(ActivityRecognition.API)
                 .addConnectionCallbacks(this)
                 .addOnConnectionFailedListener(this)
                 .build();
         broadcastReceiver = new BroadcastReceiver() {
             @Override
             public void onReceive(Context context, Intent intent) {
                 Log.d("API.ACTIVITY.RECEIVE", ActivityRecognitionResult.extractResult(intent).toString());
                 /* This DOES NOT log the activity result */
             }
         }
         googleApiClient.connect();
         // This is the thread I will use to write records on file, to do
         new Thread((Runnable) -> {
             LocalBroadcastManager.getInstance(this).registerReceiver(broadcastReceiver, new IntentFilter(ActivityRecognizedService.LOCAL_BROADCAST_NAME));
             while (true) {
                 SystemClock.sleep(250);
                 // do stuff..
             }
         }).start();
    }
    @Override
    public void onConnected(@Nullable Bundle bundle) {
        Intent intent = new Intent(this, ActivityRecognizedService.class);
        PendingIntent pendingIntent = PendingIntent.getService(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
        ActivityRecognitionClient activityRecognitionClient = ActivityRecognition.getClient(this);
        Task task = activityRecognitionClient.requestActivityUpdates(250, pendingIntent);
}
}

当然，记录收到的广播不是最终目标，因为我可以将其留在onHandleIntent()中，相反，我需要将提取的结果与我将在最后一个线程中收集的其他数据一起写入文件。我在onResume()方法中也有registerReceiver调用。

Answer 1

我认为问题是您广播了相同的传入Intent。广告它没有附加任何操作。因此，BroadcastReceiver您已注册操作"API.活动。BROADCAST_NAME"不会收到通知。

将操作设置为 Intent 。

@Override
    protected void onHandleIntent(@Nullable Intent intent) {
        Intent sendIntent=new Intent(LOCAL_BROADCAST_NAME);
        LocalBroadcastManager.getInstance(this).sendBroadcast(sendIntent);
    }