Question

我是Android的新手，我正试图在手机锁定时从onHandleIntent获取gps的单一更新。这可能吗？

这是我的代码：

public class ActivityRecognitionService extends IntentService implements LocationListener {

    private PowerManager.WakeLock mWakeLock;

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

    @Override
    protected void onHandleIntent(Intent intent) 
    {
        if (ActivityRecognitionResult.hasResult(intent)) {
            // Get the update
            ActivityRecognitionResult result =
                    ActivityRecognitionResult.extractResult(intent);
            // Get the most probable activity
            DetectedActivity mostProbableActivity =
                    result.getMostProbableActivity();

            int confidence = mostProbableActivity.getConfidence();

            if(confidence>50)
            {
                int activityType = mostProbableActivity.getType();

                checkIfGetPosition(activityType);
            }
        } 
        else {}
    }

    private void checkIfGetPosition(int activityType) 
    {
        LocationManager locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
        Criteria lCriteria = new Criteria();
        lCriteria.setBearingAccuracy(Criteria.ACCURACY_HIGH);

        long lCurrentTime = System.currentTimeMillis()/MILLISECONDS_PER_SECOND;
        lCurrentTime = lCurrentTime/SECOND_PER_MINUTE;
        Location lastLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
        long lLastTime = 0;
        if(lastLocation!=null)
            lLastTime = lastLocation.getTime()/MILLISECONDS_PER_SECOND/SECOND_PER_MINUTE;

        switch(activityType) 
        {
        case DetectedActivity.IN_VEHICLE:
            if(lCurrentTime > lLastTime+5)
            {
                aquireWakeLock();
                locationManager.requestSingleUpdate(lCriteria, this, null);
            }
            break;
        case DetectedActivity.ON_BICYCLE:
            if(lCurrentTime > lLastTime+10)
            {
                aquireWakeLock();
                locationManager.requestSingleUpdate(lCriteria, this, null);
            }
            break;
        case DetectedActivity.ON_FOOT:
            if(lCurrentTime > lLastTime+10)
            {
                aquireWakeLock();
                locationManager.requestSingleUpdate(lCriteria, this, null);
            }
            break;
        case DetectedActivity.UNKNOWN:
            if(lCurrentTime > lLastTime+15)
            {
                aquireWakeLock();
                locationManager.requestSingleUpdate(lCriteria, this, null);
            }
            break;
        case DetectedActivity.STILL:
        case DetectedActivity.TILTING:
            if(lCurrentTime > lLastTime+60)
            {
                aquireWakeLock();
                locationManager.requestSingleUpdate(lCriteria, this, null);
            }
        }
    }

    private void aquireWakeLock() {
        final PowerManager pm = (PowerManager) this.getSystemService(Context.POWER_SERVICE);
        mWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, TAG);
        mWakeLock.acquire();
    }

    private void releaseWakeLock() {
        if(mWakeLock==null) return;
        else
        {
            mWakeLock.release();
            mWakeLock = null;
        }
    }



    @Override
    public void onLocationChanged(Location location) {
        if(location.getAccuracy()!=0.0 && location.getAccuracy()<100 )
        {
            releaseWakeLock();
        }
    }

    @Override
    public void onProviderDisabled(String provider) {
        System.out.println("onProviderDisabled");
    }

    @Override
    public void onProviderEnabled(String provider) {
        System.out.println("onProviderEnabled");

    }

    @Override
public void onStatusChanged(String provider, int status, Bundle extras) {
        System.out.println("onStatusChanged: "+provider);
    }

}

当我调试它时，它永远不会在Listeners方法中响应。

Answer 1

好吧，我想通过@piotrpo解决了我的问题

locationManager.requestSingleUpdate(lCriteria, this, null);

我不知道为什么它之前没有用，但当我把它改成

时

mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);

现在它可以正常使用了！

Answer 2

您遇到的问题是requestSingleUpdate是asunc方法（您将“this”作为侦听器传递）。当onHandleIntent完成后，系统可以清理IntentService组件，所以基本上WakeLock可以释放它的所有引用并将被释放。您应该使用普通服务来处理该功能并手动管理设备的电源状态。

锁定时在IntentService中获取locationManager.requestSingleUpdate

2 个答案: