Question

我在地图活动中获取位置时遇到问题。基本上，它获得了位置，但需要很长时间（几分钟）。我使用请求单个位置更新的单例来检索我的位置。这适用于我的应用程序中的多个其他实例。但是，当我在地图活动中尝试它时，需要很长时间。这是我用来获取位置的课程：

public class SingleShotLocationProvider {

public interface LocationCallback {
    void onNewLocationAvailable(GPSCoordinates location);
}

public static void requestSingleUpdate(final Context context, final LocationCallback callback) {
    final LocationManager locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);

    //If network is available
    if (locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER)) {
        Log.i("SingleShot", "network available");
        Criteria criteria = new Criteria();
        criteria.setAccuracy(Criteria.ACCURACY_COARSE);
        try {
            locationManager.requestSingleUpdate(criteria, new LocationListener() {
                @Override
                public void onLocationChanged(Location location) {
                    callback.onNewLocationAvailable(new GPSCoordinates(location.getLongitude(), location.getLatitude()));
                }
                @Override public void onStatusChanged(String provider, int status, Bundle extras) {}
                @Override public void onProviderEnabled(String provider) {}
                @Override public void onProviderDisabled(String provider) {}
            }, null);
        }
        catch (SecurityException e){
            Log.e("Location", "security exception");
        }
    }
    //If GPS is enabled
    else if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)){
        Log.i("SingleShot", "GPS available");
        Criteria criteria = new Criteria();
        criteria.setAccuracy(Criteria.ACCURACY_FINE);
        try {
            locationManager.requestSingleUpdate(criteria, new LocationListener() {
                @Override
                public void onLocationChanged(Location location) {
                    callback.onNewLocationAvailable(new GPSCoordinates(location.getLongitude(), location.getLatitude()));
                }
                @Override public void onStatusChanged(String provider, int status, Bundle extras) {}
                @Override public void onProviderEnabled(String provider) {}
                @Override public void onProviderDisabled(String provider) {}
            }, null);
        }
        catch (SecurityException e){
            Log.e("SingleShot", "security exception");
        }
    }
    else{
        Toast.makeText(context, "No network or GPS available. Try again later.", Toast.LENGTH_LONG).show();
    }
}


public static class GPSCoordinates {
    public float longitude = -1;
    public float latitude = -1;

    public GPSCoordinates(double lon, double lat) {
        longitude = (float) lon;
        latitude = (float) lat;
    }
}
}

此课程适用于我的应用中的大多数区域。它适用于服务和片段。但是当我在我的地图活动（FragmentActivity）中使用它时，单例需要很长时间才能使用我发送它的回调。以下是我从地图活动中请求新位置的方法：

public class Traffic extends FragmentActivity
    implements OnMapReadyCallback {
    MapFragment mapFragment;
    GoogleMap map;
    //...

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_map);
        mapFragment = (MapFragment) getFragmentManager()
            .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);

        //...
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        map = googleMap;
        map.setMapType(GoogleMap.MAP_TYPE_NORMAL);

        SingleShotLocationProvider.requestSingleUpdate(getApplicationContext(), new SingleShotLocationProvider.LocationCallback() {
                @Override
                public void onNewLocationAvailable(SingleShotLocationProvider.GPSCoordinates location) {
                    Log.i(TAG, location.toString());
                }
            });
    }
}

对于为什么会花这么长时间的任何想法？

Answer 1

尝试将Criteria更改为COARSE或不太准确但足够的东西。

Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_COARSE);

https://developer.android.com/reference/android/location/Criteria.html

获取用户位置需要花费很长时间才能在Google Map FragmentActivity中

1 个答案: