在Android中使用MapController的setCenter方法时出现java空指针异常

Question

我用这个代码来设置地图的中心

mapController.setCenter(new GeoPoint((int)(location.getLatitude()*1E6), (int) (location.getLongitude()*1E6)));

其中位置定义为

locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();

criteria.setAccuracy(Criteria.ACCURACY_FINE);
criteria.setAltitudeRequired(false);
criteria.setBearingRequired(false);
criteria.setCostAllowed(true);

provider = locationManager.getBestProvider(criteria, true);

Location location = locationManager.getLastKnownLocation(provider);

我在这段代码中得到了一个空指针异常。我做错了什么

Answer 1

If the provider is currently disabled, null is returned.

您可能会从locationManager得到一个空响应。getLastKnownLocation（提供商）

http://developer.android.com/reference/android/location/LocationManager.html#getLastKnownLocation%28java.lang.String%29