活動內部的BroadcastReceiver不接收來自服務的廣播

Question

我正在制作一個具有活動和intentservice的應用程序，該應用程序在后台執行一些加速度計的工作。 我嘗試發送廣播以將我的UI從服務更新為活動。 我在活動的onCreate（）方法內創建了一個廣播接收器

public class MainActivity extends Activity {


BroadcastReceiver receiver;

public static String TAG = "vic.zerotosixty";

@Override
protected void onCreate(Bundle savedInstanceState) {


    intentFilter = new IntentFilter();
    intentFilter.addAction(SpeedService.ACTION_UPDATE_ACCELERATION);

    receiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            Log.d(TAG,"Broadcast Received");
            Bundle bundle = intent.getExtras();
            double acceleration = (double) bundle.get("acceleration");
            speedText.setText((3.6*acceleration) + " Km/h");                    //Update text field (3.6 is a unit conversion factor)
        }
    };

    registerReceiver(receiver, intentFilter);

我的服務如下所示：

public class SpeedService extends IntentService implements SensorEventListener {

public final static int METHOD_INITIALIZE = 0;
public final static int METHOD_STOP = 1;
public final static String ACTION_UPDATE_ACCELERATION = "update_acceleration";
public final static String TAG = "vic.zerotosixty";

int initialized = 0;
double x,y,z,a;

//LocalBroadcastManager broadcast;
Intent sendAcceleration;
Sensor accel;
SensorManager sm;

onHandleIntent，似乎工作正常

protected void onHandleIntent(Intent intent) {
    Bundle bundle = intent.getExtras();
    int method = (int) bundle.get("method");
    switch(method) {
        case METHOD_INITIALIZE:
            if (initialized == 0) {initialize();}
            break;
        default:
            break;
    }
}

private void initialize()         {
    Log.d(TAG, "initialized");
    sm = (SensorManager) getSystemService(SENSOR_SERVICE);
    accel = sm.getDefaultSensor(Sensor.TYPE_LINEAR_ACCELERATION);
    sm.registerListener(this, accel, SensorManager.SENSOR_DELAY_NORMAL);
    sendAcceleration = new Intent(this,MainActivity.class);
    sendAcceleration.setAction(ACTION_UPDATE_ACCELERATION);
    //broadcast = BroadcastManager.getInstance(this);

    initialized = 1;
}

這是廣播的發送來源

public void onSensorChanged(SensorEvent event) {
    x = event.values[0];
    y = event.values[1];
    z = event.values[2];
    a = Math.sqrt(Math.pow(x,2) + Math.pow(y,2) + Math.pow(z,2));

    sendAcceleration.putExtra("acceleration", a);
    sendBroadcast(sendAcceleration);
    Log.d(TAG,"broadcast sent");
}

從監視日志中可以看到發送的廣播 ，但從未收到 。 無法完成像從服務向活動中發送某些內容這樣簡單的事情，這使我望而卻步。 有任何想法嗎？

Answer 1

第一次進行此操作時，我遵循以下步驟：

https://developer.android.com/training/run-background-service/report-status.html

嘗試活動：

LocalBroadcastManager.getInstance(getActivity()).registerReceiver(receiver, intentFilter);

在服務中：

LocalBroadcastManager.getInstance(this).sendBroadcast(sendAcceleration);

Answer 2

弄清楚了...

sendAcceleration = new Intent(this,MainActivity.class);

本來應該

sendAcceleration = new Intent();