某些手机​​的Android GPS位置请求失败

Question

我目前正在使用android.location.API开发一个Android应用程序。

通常GPS定位请求在某些手机（Galaxy Note2）中成功但在其他手机中失败（getLastKnownLocation（）返回null）（Galaxy S3和S4）。

GPS很适合S3＆amp; S4如果我第一次激活三星内置功能＆＃34; GPS卫星视图＆＃34;它将扫描可用的卫星。

我的猜测是S3和＆amp; S4正在使用提供差的GPS信号的联发科技芯片。那么有谁知道如何执行像在Android中扫描卫星一样的功能？

请注意，我的应用已在中国使用，因此请不要提供任何Google相关服务。

谢谢。

public class MyLocationManager implements android.location.LocationListener{

    private static MyLocationManager instance = null;
    private Location currentLocation;
    private String provider;
    private LocationManager locationManager;
    private Context context;

    public static MyLocationManager getInstance(){
        if (instance == null){
            instance = new MyLocationManager();
        }
        return instance;
    }

    public boolean hasLocation(){
        if(currentLocation == null){
            return false;
        } else{
            return true;
        }
    }

    public float distanceInMetersFromLocation(double latitude, double longitude){
        if (currentLocation == null){
            return -1;
        }
        float[] results = new float[3];
        Location.distanceBetween(currentLocation.getLatitude(), currentLocation.getLongitude(), latitude, longitude, results);

        return results[0];
    }


    public void startListenLocation(Context context) {

        this.context = context;

        locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
        boolean gpsEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
        boolean wifiEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);

        if (gpsEnabled){
            provider = LocationManager.GPS_PROVIDER;
            Log.e("MyLocationManager", "GPS");
        } else if (wifiEnabled){
            provider = LocationManager.NETWORK_PROVIDER;
            Log.e("MyLocationManager", "NetWork");
        } else {
            Log.e("MyLocationManager", "Please Enable Location Service");
            return;
        }

        requestLocationUpdates();

        if(provider.equals(LocationManager.GPS_PROVIDER)){
            currentLocation = locationManager.getLastKnownLocation(provider);
        } else{
            currentLocation = locationManager.getLastKnownLocation(provider);
        }

        if(currentLocation == null && provider.equals(LocationManager.GPS_PROVIDER)){
            Log.e("MyLocationManager", "GPS Failed");
            if(wifiEnabled){
                Log.e("MyLocationManager", "Use Wifi");
                provider = LocationManager.NETWORK_PROVIDER;
                requestLocationUpdates();
                currentLocation = locationManager.getLastKnownLocation(provider);
            }else{
                return;
            }
        }

    }

    public void stopListenLocation(){
        //stop updating after retrieving the location
        locationManager.removeUpdates(this);
    }

    public void requestLocationUpdates(){
        if(provider != null && !provider.isEmpty()){
            locationManager.requestLocationUpdates(provider, 60000, 10, this);
        } else{
            Log.e("MyLocationManager", "Request Location Updates Failed: Provider is null.");
        }
    }


    @Override
    public void onLocationChanged(Location location) {
        currentLocation = location;
        Log.d("SONIC", "location changed to "+location);

    }

    @Override
    public void onStatusChanged(String s, int i, Bundle bundle) {

    }

    @Override
    public void onProviderEnabled(String s) {

    }

    @Override
    public void onProviderDisabled(String s) {

    }

}

Answer 1

实际上这是设备问题。

某些设备不支持getLastKnownLocation（例如Motorola XT720）。您必须自己实施LocationListener并将onLocationChanged中的位置更新保存到数据库或sharedpreferences。当getLastKnownLocation为null时，请使用保存的位置。

您可以采用最佳提供商方式尽可能快地获取位置。

阅读this博客希望它对您有所帮助。