Question

我正在写一个应用程序，每隔10秒就会得到我的坐标并发送到服务器。我有一个服务，每10秒（用AlarmManager实现）获得当前的GPS坐标。但它总是只显示第一个获得协调，为什么？

public class GpsService extends Service implements LocationListener {
// flag for GPS status
boolean isGPSEnabled = false;


// flag for GPS status
boolean canGetLocation = false;

// Declaring a Location Manager
private LocationManager locationManager;

Location location; // location
double latitude; // latitude
double longitude; // longitude

// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 5; // 10 meters

// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 10 * 1; // 1 minute

@Override
public void onCreate() {
    Log.i("myLogs", "onCreate");
    super.onCreate();
}
@Override
public IBinder onBind(Intent arg0) {
    Log.i("myLogs", "onBind");
    return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    Log.i("myLogs", "onStartCommand");
    getLocation();
    if(location != null) {
        Log.i("myLogs", "lat = " + Double.toString(location.getLatitude()) + "lng = " + Double.toString(location.getLongitude()));
    }
    else
        Log.i("myLogs", "no location for your today");
    return super.onStartCommand(intent, flags, startId);
}
@Override
public void onDestroy() {
    Log.i("myLogs", "onDestroy");
    super.onDestroy();
}
public Location getLocation() {
    try {
        locationManager = (LocationManager) this
                .getSystemService(LOCATION_SERVICE);

        // getting GPS status
        isGPSEnabled = locationManager
                .isProviderEnabled(LocationManager.GPS_PROVIDER);

        if (!isGPSEnabled) {
            stopSelf();
        } else {
            this.canGetLocation = true;
            // if GPS Enabled get lat/long using GPS Services
            if (isGPSEnabled) {
                if (location == null) {
                    locationManager.requestLocationUpdates(
                            LocationManager.GPS_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                    Log.d("myLogs", "GPS Enabled");
                    if (locationManager != null) {
                        location = locationManager
                                .getLastKnownLocation(LocationManager.GPS_PROVIDER);
                        if (location != null) {
                            latitude = location.getLatitude();
                            longitude = location.getLongitude();
                        }
                    }
                }
            }
        }

    } catch (Exception e) {
        e.printStackTrace();
    }

    return location;
}

}

Answer 1

如果此代码首次执行，location为null 所以它将分配最新的位置

在第二次传递时，它不为空，因此它会跳过整个部分而不会更新location或latitude或longitude

if (location == null) {
                    locationManager.requestLocationUpdates(
                            LocationManager.GPS_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                    Log.d("myLogs", "GPS Enabled");
                    if (locationManager != null) {
                        location = locationManager
                                .getLastKnownLocation(LocationManager.GPS_PROVIDER);

                        if (location != null) {
                            latitude = location.getLatitude();
                            longitude = location.getLongitude();
                        }
                    }
                }

Answer 2

要确保获得最新且准确的位置，您需要实现位置监听器方法。您还应注册广播接收器以收听位置变化。 Here是一篇博文，详细解释了所有这些内容。它会根据准确性和新鲜度监听位置更改并更新位置。

GPS位置永远不会改变

2 个答案: