使用runtime for Android加载离线地图包mmpk失败问题

    mMapView = (MapView) findViewById(R.id.mapView);

    final MobileMapPackage mapPackage = new MobileMapPackage(Environment.getExternalStorageDirectory() + "/ArcGIS/test.mmpk");



    mapPackage.loadAsync();

    mapPackage.addDoneLoadingListener(new Runnable(){

      @Override

      public void run() {

        if (mapPackage.getLoadStatus() == LoadStatus.LOADED) {

          mMapView.setMap(mapPackage.getMaps().get(0));

        }

      }

    });