Question

我正在开发一款应用程序，如果用户位于特定区域内，该应用应能持续获得准确的用户位置。位置更新应保存在服务器（Parse.com）上，以便其他用户可以获取用户的当前位置。

流程是：

申请onCreate - ＆gt;
使用LocationListener启动服务 - ＆gt;
onLocationChanged - ＆gt;
在Parse.com上保存新位置 - ＆gt;
Parse.com Cloud afterSave方法向用户发送推送通知 - ＆gt;
其他用户通过广播接收方获得通知 - ＆gt;
在地图上更新用户标记＆lt; -

问题：

我不确定如何实现第4步，我是否应该在onLocationChanged方法内的parse中保存新位置？我应该将它传递给BroadcastReciever并将其保存在那里解析吗？或者我应该将它传递给我的CurrentUser类中的静态方法，该方法将在服务器上执行保存？
我注意到requestLocationUpdates文档说：

＆＃34;此方法适用于前台用例，更具体地说用于在连接到LocationClient时请求位置。对于后台用例，PendingIntent版本的方法是。推荐＆＃34;

在我的情况下，我应该使用哪种方法？
我应该使用什么值来获得几乎实时的位置而不会每小时消耗超过5％的电池电量？

我的服务类：

public class UserTracker extends Service implements
GooglePlayServicesClient.ConnectionCallbacks,
GooglePlayServicesClient.OnConnectionFailedListener, LocationListener{

static int GEOFENCE_STATUS; 
final static int INSIDE_GEOFENCE = 9001, OUTSIDE_GEOFENCE = 9002;

static final int MINIMUM_ACCURACY = 26;

final static int GEOFENCE_RADIUS = 2000;

static final int NULL_LOCATION_ERROR = 7001;

static final int INSIDE_INTERVAL = 10000, INSIDE_FASTEST_INTERVAL = 1000, INSIDE_SMALLEST_DISPLACEMENT = 10;
static final int OUTSIDE_INTERVAL = 300000, OUTSIDE_FASTEST_INTERVAL = 60000, OUTSIDE_SMALLEST_DISPLACEMENT = 100;

static Location eventLocation;

LocationClient lc;

@Override
public void onCreate() {
    super.onCreate();
    eventLocation = new Location("Test");
    lc = new LocationClient(getApplicationContext(), this, this);
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {

    double eventLat = intent.getDoubleExtra("Latitude", -1);
    double eventLon = intent.getDoubleExtra("Longitude", -1);
    if (eventLat == -1 || eventLon == -1) {
        stopSelf();
        return START_REDELIVER_INTENT;
    }

    eventLocation.setLatitude(eventLat);
    eventLocation.setLongitude(eventLon);

    lc.connect();

    return START_STICKY;
}

public int getGeofenceStatus(Location currentLocation) {
    if (currentLocation == null) {          
        return NULL_LOCATION_ERROR;         
    } 
    if (currentLocation.distanceTo(eventLocation) > GEOFENCE_RADIUS) {
        Log.d(TAG, "User is outside geofence");
        return OUTSIDE_GEOFENCE;
    } else {
        Log.d(TAG, "User is inside geofence");
        return INSIDE_GEOFENCE;
    }
}

public void requestLocationUpdates(int status) {

    GEOFENCE_STATUS = status;

    LocationRequest request = LocationRequest.create();

    switch (status) {
    case NULL_LOCATION_ERROR:
        stopSelf();
        break;
    case INSIDE_GEOFENCE:           
        request.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        request.setInterval(INSIDE_INTERVAL);
        request.setFastestInterval(INSIDE_FASTEST_INTERVAL);
        request.setSmallestDisplacement(INSIDE_SMALLEST_DISPLACEMENT);
        break;
    case OUTSIDE_GEOFENCE:
        request.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
        request.setInterval(OUTSIDE_INTERVAL);
        request.setFastestInterval(OUTSIDE_FASTEST_INTERVAL);
        request.setSmallestDisplacement(OUTSIDE_SMALLEST_DISPLACEMENT);         
        break;
    }
    lc.requestLocationUpdates(request, this);
}

@Override
public void onLocationChanged(Location location) {
    int newStatus = getGeofenceStatus(location);
    int accuracy = (int) location.getAccuracy(); 

    String message = "Geofence status: " + newStatus + 
            "\nAccuracy: " + accuracy + 
            "\nDistance to event: " + location.distanceTo(eventLocation);
    Toast.makeText(getApplicationContext(), message, Toast.LENGTH_SHORT).show();

    if (newStatus == INSIDE_GEOFENCE && accuracy < MINIMUM_ACCURACY) {
        Log.d(TAG, "Accuracy is good");
                    // do the save on server procees
    }
    if (GEOFENCE_STATUS != newStatus) {
        requestLocationUpdates(newStatus);
    }       
}

@Override
public void onConnectionFailed(ConnectionResult result) {
    Log.d(TAG, "LocationClient connection failed: " + result.getErrorCode());
}

@Override
public void onConnected(Bundle arg0) {
    Location currentLocation = lc.getLastLocation();
    requestLocationUpdates(getGeofenceStatus(currentLocation));
}

@Override
public void onDisconnected() {
    Log.d(TAG, "LocationClient disconnected");
}

@Override
public IBinder onBind(Intent intent) {
    return null;
}       
}

如何在Android中的服务中处理位置侦听器更新？

0 个答案: