描述
反向地理编码确定地图上给出点的地址。本例展示了如何通过ArcGIS JavaScript API做反向地理编码。
反向地理编码和常规的地理编码请求都使用Locator类和ArcGIS Server geocode service。 调用 locationToAddress方法(和常规的地理编码相反 addressToLocations)进行反向地理编码。下面的监听器捕获鼠标单击事件并为单击的点调用locationToAddress方法:
dojo.connect(map, "onClick", function(evt) {
map.graphics.clear();
locator.locationToAddress(evt.mapPoint, 100);
});
onLocationToAddressComplete事件的监听器传递最好的AddressCandidate给一个回调函数。然后回调函数结合候选的点和图形并增加到地图里。函数也使用 InfoTemplate格式化一个单击图形显示的InfoWindow。注意为了定位信息窗口，地址结果的地图点必须被转换为一个屏幕点。
var screenPnt = map.toScreen(candidate.location);
map.infoWindow.show(screenPnt,map.getInfoWindowAnchor(screenPnt));
为了保持信息窗口总是可见的，信息窗口位于锚点所在的四分之一地图的相反方向。例如，如果点位于地图右上角，信息窗口显示在点的左下方。
1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> 2 <html> 3 <head> 4 <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> 5 <meta http-equiv="X-UA-Compatible" content="IE=7" /> 6 <title>Find Address</title> 7 <link rel="stylesheet" type="text/css" href="http://serverapi.arcgisonline.com/jsapi/arcgis/1.5/js/dojo/dijit/themes/tundra/tundra.css"> 8 <script type="text/javascript" src="http://serverapi.arcgisonline.com/jsapi/arcgis/?v=1.5"></script> 9 <script type="text/javascript"> 10 dojo.require("esri.map"); 11 dojo.require("esri.tasks.locator"); 12 13 function init() { 14 15 //创建地图并添加 16 var map = new esri.Map("map",{ extent: new esri.geometry.Extent(-95.2991, 38.9379, -95.2476, 38.963, new esri.SpatialReference({wkid:4326}))}); 17 var tiledMapServiceLayer = new esri.layers.ArcGISTiledMapServiceLayer("http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap_World_2D/MapServer"); 18 map.addLayer(tiledMapServiceLayer); 19 20 var locator = new esri.tasks.Locator("http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Locators/ESRI_Geocode_USA/GeocodeServer"); 21 22 //设置显示窗口的格式 23 var infoTemplate = new esri.InfoTemplate("Location","Street: ${Address}<br />City: ${City}<br />State:${State}<br />Zip:${Zip}"); 24 //设置样式：圆，实心，蓝色 25 var symbol = new esri.symbol.SimpleMarkerSymbol(esri.symbol.SimpleMarkerSymbol.STYLE_CIRCLE, 15, new esri.symbol.SimpleLineSymbol(esri.symbol.SimpleLineSymbol.STYLE_SOLID, new dojo.Color([0,0,255]),2), new dojo.Color([0,0,255])); 26 // 27 dojo.connect(locator,"onLocationToAddressComplete",function(candidate) {//事件的监听器 28 if (candidate.address) { 29 var graphic = new esri.Graphic(candidate.location, symbol, candidate.address, infoTemplate); 30 map.graphics.add(graphic); 31 map.infoWindow.setTitle(graphic.getTitle()); 32 map.infoWindow.setContent(graphic.getContent()); 33 var screenPnt = map.toScreen(candidate.location); 34 map.infoWindow.show(screenPnt,map.getInfoWindowAnchor(screenPnt)); 35 } 36 37 }); 38 39 dojo.connect(map, "onClick", function(evt) { 40 map.graphics.clear(); 41 locator.locationToAddress(evt.mapPoint, 100); 42 }); 43 } 44 dojo.addOnLoad(init); 45 </script> 46 </head> 47 <body class="tundra"> 48 Left click on the map to get address. 49 <div id="map" style="1200px; height:600px; border:1px solid #000;"></div> 50 </body> 51 </html> 52 53 54