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

Java 在Android中使用MapController的setCenter方法时出现空指针异常,java,android,android-maps,Java,Android,Android Maps,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();

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

如果提供程序当前已禁用,则返回null

您可能从locationManager.getLastKnownLocation(提供程序)获得空响应


mapController.setCenter线