Android GIS开发系列-- 入门季（15） 网络图层加载
一、首先我们来看一个网络图层：
http://services.arcgisonline.com/arcgis/rest/services/World_Street_Map/MapServer，这是全球街道图。加载的代码也很简单：
private static final String WORLD_STREETS_URL = "http://services.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer"; private MapView mMapView = null; private ArcGISTiledMapServiceLayer mWorldStreetsLayer = null; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mMapView = (MapView) findViewById(R.id.map_view); mWorldStreetsLayer = new ArcGISTiledMapServiceLayer(WORLD_STREETS_URL); mMapView.addLayer(mWorldStreetsLayer); mWorldStreetsLayer.setOnStatusChangedListener(new OnStatusChangedListener() { @Override public void onStatusChanged(Object o, STATUS status) { if (status==STATUS.INITIALIZED){ Log.i("huang","加载成功"); }else if(status==STATUS.INITIALIZATION_FAILED||status==STATUS.LAYER_LOADING_FAILED){ Log.i("huang","加载失败"); } } }); }
效果图
问：为什么用ArcGISTiledMapServiceLayer 加载而不用其他图层加载呢？
用浏览器打开
http://services.arcgisonline.com/arcgis/rest/services/World_Street_Map/MapServer，可以看到详细信息。
它的子图层只有一个：
下面是坐标信息，注意Single Fused Map Cache: true，支持缓存。
与Tile Info信息，
通过信息说明这是一个TiledLayer,而ArcGISTiledMapServiceLayer是TiledLayer子类的子类，看一下ArcGISTiledMapServiceLayer的介绍 
点开World Street Map链接，
http://services.arcgisonline.com/arcgis/rest/services/World_Street_Map/MapServer/0，这是它的唯一子图层。真正加载的也是这个图层 
Type虽然说是FeatureLayer，但它得用ArcGISFeatureLayer加载。
ArcGISFeatureLayer arcGISFeatureLayer = new ArcGISFeatureLayer(WORLD_STREETS_URL+"/0", ArcGISFeatureLayer.MODE.ONDEMAND); SimpleFillSymbol simpleFillSymbol = new SimpleFillSymbol(Color.argb(0,0,0,0),SimpleFillSymbol.STYLE.SOLID); mMapView.addLayer(arcGISFeatureLayer); arcGISFeatureLayer.setRenderer(new SimpleRenderer(simpleFillSymbol)); arcGISFeatureLayer.setOnStatusChangedListener(new OnStatusChangedListener() { @Override public void onStatusChanged(Object o, STATUS status) { if (status==STATUS.INITIALIZED){ Log.i("huang","加载成功"); }else if(status==STATUS.INITIALIZATION_FAILED||status==STATUS.LAYER_LOADING_FAILED){ Log.i("huang","加载失败"); } } });
上面虽然加载成功，但并看不到图层，而且报错：
FeatureSetCallback.onError
com.esri.core.io.EsriServiceException: Requested operation is not supported by this service. The requested capability is not supported.
仔细再看网络信息，
大体上知道为什么报 The requested capability is not supported。也就是不能用这种方法加载，而得用前面的代码加载！！！
ArcGISDynamicMapServiceLayer
服务地址：
http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StateCityHighway_USA/MapServer，这是美国的高铁图。
用浏览器打开，有三个子图层，Single Fused Map Cache: false！ 
下面是ArcGISDynamicMapServiceLayer的介绍： 
加载代码 ：
private static final String DYNAMIC_USA_HIGHWAY_URL = "http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StateCityHighway_USA/MapServer"; private ArcGISDynamicMapServiceLayer usaHighwayLayer = null; private MapView mMapView = null; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mMapView = (MapView) findViewById(R.id.map_view); usaHighwayLayer = new ArcGISDynamicMapServiceLayer(DYNAMIC_USA_HIGHWAY_URL); mMapView.addLayer(usaHighwayLayer); usaHighwayLayer.setOnStatusChangedListener(new OnStatusChangedListener() { @Override public void onStatusChanged(Object o, STATUS status) { if (status==STATUS.INITIALIZED){ Log.i("huang","加载成功"); }else if(status==STATUS.INITIALIZATION_FAILED||status==STATUS.LAYER_LOADING_FAILED){ Log.i("huang","加载失败"); } } });}
效果图
二、ArcGISFeatureLayer加载图层
服务地图
http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StateCityHighway_USA/MapServer/0，也就是上面服务的子图层。
ArcGISFeatureLayer arcGISFeatureLayer = new ArcGISFeatureLayer("http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StateCityHighway_USA/MapServer/0", ArcGISFeatureLayer.MODE.ONDEMAND);
mMapView.addLayer(arcGISFeatureLayer);
arcGISFeatureLayer.setRenderer(new SimpleRenderer(new SimpleLineSymbol(Color.argb(250, 52, 17, 255),2))); arcGISFeatureLayer.setOnStatusChangedListener(new OnStatusChangedListener() { @Override public void onStatusChanged(Object o, STATUS status) { if (status==STATUS.INITIALIZED){ Log.i("huang","加载成功"); }else if(status==STATUS.INITIALIZATION_FAILED||status==STATUS.LAYER_LOADING_FAILED){ Log.i("huang","加载失败"); } } });注意要设置setRenderer，效果 
ArcGISFeatureLayer 具有FeatureLayer的一些查询方法，与前面几讲里FeatureLayer查询相似，这里不再讲了。
//查询要素方法
queryIds(Query query, CallbackListener<int[]> callback)
queryFeatures(Query query, CallbackListener<FeatureSet> callback)
点击Query进入查询要素界面，可直接 查询要素
where 1=1，点击Query(GET)，可得到以下结果集
