摘自http://www.mapgx.com/Portal/api/JS/help/jssamples/util_project.html
查看在线示例
描述
本例展示了如何用多个坐标系统查找一个点的坐标。在地图上单击一个点查看它的坐标（WGS 1984 Web Mercator投影坐标系统）。看到的这个坐标需要一个投影因为从鼠标单击得到的点的地理坐标（经度和纬度）。能够通过单击信息窗口上的按钮投影这个坐标回到地理坐标。
投影使用 ArcGIS Server几何服务实现。这个服务类型是在ArcGIS Server 9.3增加的，可以用使用几何服务在JavaScript应用中缓冲，投影和简化几何体。这行代码创建了几何服务:
gsvc = new esri.tasks.GeometryService("http://sampleserver1a.arcgisonline.com/arcgis/rest/services/Geometry/GeometryServer");
能使用服务目录查出自己的几何服务的URL。由于服务的名称必须是Geometry，因此URL和这个极其相似。
当单击点时间到的窗口是一个信息窗口。信息窗口通过InfoTemplate进行格式化，能够包含HTML，因此可以在信息窗口里面放置按钮。注意空的ID = 'latlong'的DIV被放在信息模板中。如果单击按钮将坐标转回经纬度，这个DIV被填充。
代码
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>Project a point</title>
7
8 <link rel="stylesheet" type="text/css" href="http://serverapi.arcgisonline.com/jsapi/arcgis/1.5/js/dojo/dijit/themes/tundra/tundra.css">
9 <script src="http://serverapi.arcgisonline.com/jsapi/arcgis/?v=1.5" type="text/javascript"></script>
10
11 <script type="text/javascript">
12 dojo.require("esri.map");
13 dojo.require("esri.tasks.geometry");
14
15 var map = null;
16 var gsvc = null;
17 var pt = null;
18
19 function initialize() {
20 map = new esri.Map("map");
21 var layer = new esri.layers.ArcGISTiledMapServiceLayer("http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap_World_2D/MapServer");
22 map.addLayer(layer);
23 map.setExtent(new esri.geometry.Extent(-144.13584773952124, 7.981485927970198, -52.76454682003924, 68.8956865409582, new esri.SpatialReference({wkid: 4326})));
24
25 gsvc = new esri.tasks.GeometryService("http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer");
26 dojo.connect(map, "onClick", projectToWebMercator);
27 }
28
29 function projectToWebMercator(evt) {
30 map.graphics.clear();
31 var point = evt.mapPoint;
32 var symbol = new esri.symbol.SimpleMarkerSymbol().setStyle(esri.symbol.SimpleMarkerSymbol.STYLE_DIAMOND);
33 var graphic = new esri.Graphic(point, symbol);
34 var outSR = new esri.SpatialReference({ wkid: 102113});
35 map.graphics.add(graphic);
36
37 gsvc.project([ graphic ], outSR, function(features) {
38 pt = features[0].geometry;
39 graphic.setInfoTemplate(new esri.InfoTemplate("Coordinates",
40 "<p> X: " + pt.x +
41 "<br/> Y: " + pt.y +
42 "</p>" +
43 "<input type='button' value='Convert back to LatLong' onclick='projectToLatLong();' />" +
44 "<div id='latlong'></div>"));
45 map.infoWindow
46 .setTitle(graphic.getTitle())
47 .setContent(graphic.getContent())
48 .show(evt.screenPoint, map.getInfoWindowAnchor(evt.screenPoint));
49 });
50 }
51
52 function projectToLatLong() {
53 var symbol = new esri.symbol.SimpleMarkerSymbol();
54 var graphic = new esri.Graphic(pt, symbol);
55 var outSR = new esri.SpatialReference({ wkid: 4326});
56
57 gsvc.project([ graphic ], outSR, function(features) {
58 pt = features[0].geometry;
59 dojo.byId("latlong").innerHTML = " Latitude = " + pt.y + "<br/> Longitude = " + pt.x;
60 });
61 }
62
63 dojo.addOnLoad(initialize);
64 </script>
65
66 </head>
67
68 <body class="tundra">
69 <b>Click a location on the map to Project from LatLng -> Web Mercator:</b>
70 <div id="map" style="600px; height:400px; border:1px solid #000;"></div>
71 </body>
72
73 </html>
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>Project a point</title>
7
8 <link rel="stylesheet" type="text/css" href="http://serverapi.arcgisonline.com/jsapi/arcgis/1.5/js/dojo/dijit/themes/tundra/tundra.css">
9 <script src="http://serverapi.arcgisonline.com/jsapi/arcgis/?v=1.5" type="text/javascript"></script>
10
11 <script type="text/javascript">
12 dojo.require("esri.map");
13 dojo.require("esri.tasks.geometry");
14
15 var map = null;
16 var gsvc = null;
17 var pt = null;
18
19 function initialize() {
20 map = new esri.Map("map");
21 var layer = new esri.layers.ArcGISTiledMapServiceLayer("http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap_World_2D/MapServer");
22 map.addLayer(layer);
23 map.setExtent(new esri.geometry.Extent(-144.13584773952124, 7.981485927970198, -52.76454682003924, 68.8956865409582, new esri.SpatialReference({wkid: 4326})));
24
25 gsvc = new esri.tasks.GeometryService("http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer");
26 dojo.connect(map, "onClick", projectToWebMercator);
27 }
28
29 function projectToWebMercator(evt) {
30 map.graphics.clear();
31 var point = evt.mapPoint;
32 var symbol = new esri.symbol.SimpleMarkerSymbol().setStyle(esri.symbol.SimpleMarkerSymbol.STYLE_DIAMOND);
33 var graphic = new esri.Graphic(point, symbol);
34 var outSR = new esri.SpatialReference({ wkid: 102113});
35 map.graphics.add(graphic);
36
37 gsvc.project([ graphic ], outSR, function(features) {
38 pt = features[0].geometry;
39 graphic.setInfoTemplate(new esri.InfoTemplate("Coordinates",
40 "<p> X: " + pt.x +
41 "<br/> Y: " + pt.y +
42 "</p>" +
43 "<input type='button' value='Convert back to LatLong' onclick='projectToLatLong();' />" +
44 "<div id='latlong'></div>"));
45 map.infoWindow
46 .setTitle(graphic.getTitle())
47 .setContent(graphic.getContent())
48 .show(evt.screenPoint, map.getInfoWindowAnchor(evt.screenPoint));
49 });
50 }
51
52 function projectToLatLong() {
53 var symbol = new esri.symbol.SimpleMarkerSymbol();
54 var graphic = new esri.Graphic(pt, symbol);
55 var outSR = new esri.SpatialReference({ wkid: 4326});
56
57 gsvc.project([ graphic ], outSR, function(features) {
58 pt = features[0].geometry;
59 dojo.byId("latlong").innerHTML = " Latitude = " + pt.y + "<br/> Longitude = " + pt.x;
60 });
61 }
62
63 dojo.addOnLoad(initialize);
64 </script>
65
66 </head>
67
68 <body class="tundra">
69 <b>Click a location on the map to Project from LatLng -> Web Mercator:</b>
70 <div id="map" style="600px; height:400px; border:1px solid #000;"></div>
71 </body>
72
73 </html>
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>Project a point</title>
7
8 <link rel="stylesheet" type="text/css" href="http://serverapi.arcgisonline.com/jsapi/arcgis/1.5/js/dojo/dijit/themes/tundra/tundra.css">
9 <script src="http://serverapi.arcgisonline.com/jsapi/arcgis/?v=1.5" type="text/javascript"></script>
10
11 <script type="text/javascript">
12 dojo.require("esri.map");
13 dojo.require("esri.tasks.geometry");
14
15 var map = null;
16 var gsvc = null;
17 var pt = null;
18
19 function initialize() {
20 map = new esri.Map("map");
21 var layer = new esri.layers.ArcGISTiledMapServiceLayer("http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap_World_2D/MapServer");
22 map.addLayer(layer);
23 map.setExtent(new esri.geometry.Extent(-144.13584773952124, 7.981485927970198, -52.76454682003924, 68.8956865409582, new esri.SpatialReference({wkid: 4326})));
24
25 gsvc = new esri.tasks.GeometryService("http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer");
26 dojo.connect(map, "onClick", projectToWebMercator);
27 }
28
29 function projectToWebMercator(evt) {
30 map.graphics.clear();
31 var point = evt.mapPoint;
32 var symbol = new esri.symbol.SimpleMarkerSymbol().setStyle(esri.symbol.SimpleMarkerSymbol.STYLE_DIAMOND);
33 var graphic = new esri.Graphic(point, symbol);
34 var outSR = new esri.SpatialReference({ wkid: 102113});
35 map.graphics.add(graphic);
36
37 gsvc.project([ graphic ], outSR, function(features) {
38 pt = features[0].geometry;
39 graphic.setInfoTemplate(new esri.InfoTemplate("Coordinates",
40 "<p> X: " + pt.x +
41 "<br/> Y: " + pt.y +
42 "</p>" +
43 "<input type='button' value='Convert back to LatLong' onclick='projectToLatLong();' />" +
44 "<div id='latlong'></div>"));
45 map.infoWindow
46 .setTitle(graphic.getTitle())
47 .setContent(graphic.getContent())
48 .show(evt.screenPoint, map.getInfoWindowAnchor(evt.screenPoint));
49 });
50 }
51
52 function projectToLatLong() {
53 var symbol = new esri.symbol.SimpleMarkerSymbol();
54 var graphic = new esri.Graphic(pt, symbol);
55 var outSR = new esri.SpatialReference({ wkid: 4326});
56
57 gsvc.project([ graphic ], outSR, function(features) {
58 pt = features[0].geometry;
59 dojo.byId("latlong").innerHTML = " Latitude = " + pt.y + "<br/> Longitude = " + pt.x;
60 });
61 }
62
63 dojo.addOnLoad(initialize);
64 </script>
65
66 </head>
67
68 <body class="tundra">
69 <b>Click a location on the map to Project from LatLng -> Web Mercator:</b>
70 <div id="map" style="600px; height:400px; border:1px solid #000;"></div>
71 </body>
72
73 </html>