Android studio
DatasetVector networkDataset = (DatasetVector) m_Workspace.getDatasources().get("hanghai").getDatasets().get(networkDatasetName);，这一句代码报空指针是哪里出了问题
m_Navigation2 = m_MapControl.getNavigation2();
m_Navigation2.setPathVisible(true);
m_Navigation2.setNetworkDataset(networkDataset);
m_Navigation2.loadModel( SDCARD + "/SuperMap/Try/NetworkModel.snm"); 
