为什么didRangeBeaconsInRegion多次调用？

Question

public class BeaconMonitoringService extends Service implements BootstrapNotifier, BeaconConsumer, RangeNotifier {



private static final String TAG = "BeaconMonitoringService";



private BeaconManager beaconManager;



@SuppressWarnings("unused")

private RegionBootstrap regionBootstrap;

@SuppressWarnings("unused")

private BackgroundPowerSaver backgroundPowerSaver;

private Region region;



@Override

public void onCreate() {

    super.onCreate();

    beaconSession = new BeaconSession(this);

    beaconManager = BeaconManager.getInstanceForApplication(this);

    beaconManager.getBeaconParsers().clear();



    beaconManager.getBeaconParsers().add(new BeaconParser().setBeaconLayout("m:2-3=0215,i:4-19,i:20-21,i:22-23,p:24-24"));

    region = new Region("MyBeacon", Identifier.parse("0800200C9A66"), null, null);

    regionBootstrap = new RegionBootstrap(this, region);

    beaconManager.setBackgroundMode(true);

    backgroundPowerSaver = new BackgroundPowerSaver(this);

    beaconManager.bind(this);

}



@Override

public void didEnterRegion(Region region) {

    try {

        Log.d(TAG, "Did Enter Region.");

        beaconManager.startRangingBeaconsInRegion(region);

    } catch (RemoteException e) {

        if (BuildConfig.DEBUG) Log.d(TAG, "Can't start ranging");

    }

}



@Override

public void didExitRegion(Region region) {

    try {

        Log.d(TAG, "Did Exit Region");

    } catch (RemoteException e) {

        if (BuildConfig.DEBUG) Log.d(TAG, "Can't start ranging");

    }

}



@Override

public void didDetermineStateForRegion(int state, Region region) {

    switch (state) {

        case MonitorNotifier.INSIDE:

            Log.d(TAG, "INSIDE");

            didEnterInRegion = true;

            break;

        case MonitorNotifier.OUTSIDE:

            Log.d(TAG, "OUTSIDE");

            didEnterInRegion = false;

            break;

        default:

            didEnterInRegion = false;

            Log.d(TAG, "state" + state);

            break;

    }



}



@Override

public void didRangeBeaconsInRegion(Collection<Beacon> beacons, Region region) {

    if (beacons.size() > 0) {

            for (Beacon beacon : beacons) {



             if (beacon.getId1().equals(Identifier.parse("0800200C9A66")) && beacon.getDistance() < 1.0) {

                         sendNotification(beacon);

                    }

            }

    }

}



@Override

public void onBeaconServiceConnect() {

    beaconManager.addRangeNotifier(this);

    try {

        beaconManager.startRangingBeaconsInRegion(region);

    } catch (RemoteException e) {

    }

}



@Override

public IBinder onBind(Intent intent) {

    return null;

}



@Override

public void onDestroy() {

    beaconManager.unbind(this);

    super.onDestroy();

}

Answer 1

didrangeBeaconsinRegion被设计为在每个扫描周期结束时（默认为每1秒）定时触发，以告诉您在此期间看到了哪些信标。

如果只希望在检测到每个信标之前触发一次事件，可以创建一个类变量来保存一个标志，指示是否已经处理了每个信标。

像这样：

// Put this at your class level
Set<String> mBeaconsProcessed = new HashSet<>();

...

// Put this code inside your didRangeBeaconsInRegion method

// Only process this beacon if we have not done so before
if (!mBeaconsProcessed.contains(beacon.toString)) {
    if (beacon.getId1().equals(Identifier.parse("0800200C9A66")) && beacon.getDistance() < 1.0) {
         sendNotification(beacon);
         // Mark this beacon as having already been processed.
         mBeaconsProcessed.put(beacon.toString));
         }
    }
}