Question

我正在使用以下课程从黑莓手机获取GPS位置，但我总是获得零长度和纬度值。那是为什么？

public class LocationTracker extends TimerTask {

private double longitude;
private double latitude;
private double altitude;
private LocationProvider lp;

public LocationTracker() {

    super();
    // Set criteria for selecting a location provider:
    Criteria cr = new Criteria();
    cr.setCostAllowed(true);
    cr.setPreferredResponseTime(60);
    cr.setHorizontalAccuracy(Criteria.NO_REQUIREMENT);
    cr.setVerticalAccuracy(Criteria.NO_REQUIREMENT);
    cr.setAltitudeRequired(true);
    cr.isSpeedAndCourseRequired();
    cr.isAddressInfoRequired();

    cr.setPreferredPowerConsumption(Criteria.POWER_USAGE_HIGH);

    try {
        LocationProvider lp = LocationProvider.getInstance(cr);


        Location location = null;
        try {
            location = lp.getLocation(-1);

        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }catch (LocationException e){
            System.out.println(e.toString());
        }catch(Exception e ){
            System.out.println(e.toString());
        }

        longitude = location.getQualifiedCoordinates().getLongitude();
        latitude = location.getQualifiedCoordinates().getLatitude();
        altitude = location.getQualifiedCoordinates().getAltitude();

        if (lp != null) {
            lp.reset(); 
            lp.setLocationListener(null, -1, -1, -1);               
            lp = LocationProvider.getInstance(cr);
            lp.setLocationListener(new MyLocationListener(), 2, -1, -1);
        }
         System.out.println("Lon" + longitude + " Lat "+ latitude);
    } catch (LocationException le) {
        System.out.println(le.toString());
    }catch(Exception e ){
        System.out.println(e.toString());
    }

}

public void run() {

}

public double getLongitude() {
    return longitude;
}

public double getLatitude() {
    return latitude;
}

public double getAltitude() {
    return altitude;
}

private class MyLocationListener implements LocationListener {

    public void locationUpdated(LocationProvider provider, Location location) {

        if (location != null && location.isValid()) {
            QualifiedCoordinates qc = location.getQualifiedCoordinates();

            try {
                latitude = qc.getLatitude();
                longitude = qc.getLongitude();
                altitude = qc.getAltitude();
            } catch (Exception e) {
                System.out.println(e.toString());
            }
        }
    }

    public void providerStateChanged(LocationProvider provider, int newState) {
        // TODO: if provider was disabled, then disable reporting
    }
}

}

Answer 1

您是否从设置中检查了GPS状态？如果它正在工作，请尝试将超时值设置为大约300秒而不是-1。

Answer 2

LocationProvider可能会返回Location个isValid() {{}}}对象。这样做是为了通过getExtraInfo()方法提供额外的信息。

黑莓GPS在经度和纬度上返回零

2 个答案: