ArcGIS for android的一个定位程序打不开本地的tpk文件

在网上找的一个Android定位程序，为什么总是打不开本地的tpk地图，，代码如下：

public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
map = (MapView) findViewById(R.id.map);

    local = new ArcGISLocalTiledLayer("file:///sdcard/arcgis/map.tpk");
    map.addLayer(local);

    mLocClient = new LocationClient(getApplicationContext());       
    mLocClient.registerLocationListener(new BDLocationListenerImpl());

     /**
      * LocationClientOption 
      */            
    LocationClientOption option = new LocationClientOption();           
    option.setOpenGps(true);            
    option.setAddrType("all");  
    option.setCoorType("bd09ll");
    option.setPriority(LocationClientOption.GpsFirst);  
    option.setScanSpan(1000); 
    option.disableCache(true);      
    mLocClient.setLocOption(option);  



    gLayerGps = new GraphicsLayer();
    map.addLayer(gLayerGps);

    btnGPS=(Button)findViewById(R.id.btnStartGps);
    btnGPS.setOnClickListener(new OnClickListener(){

    本人刚刚接触Android开发，求大神指教

可以参考以下链接

http://bbs.csdn.net/topics/390479916

local=new ArcGISLocalTiledLayer("file:///mnt/sdcard/ArcGIS/Basemap/Layers");

或者local = new ArcGISLocalTiledLayer("file:///storage/sdcard0/ArcGIS/Basemap/Layers")

记得用sdcard时要关掉USB的手机存储