使用Java的ArcGis Api将经纬度转换为XY坐标

Question

Hello i'm trying to convert long,lat values to X,Y using ArcGis Api For Javascript

 var i = esri.geometry.lngLatToXY(3.13, 36.742)
 console.log(i); //returns Array [ 348541.32567373366, 4403205.668961807 ]

in what system does this conversion take place? is there a method to specify the projection system?

note: the conversion is done from decimal degree to meters

i followed this : https://developers.arcgis.com/javascript/3/jsapi/esri.geometry.webmercatorutils-amd.html

Answer 1

This method is used to convert geographic coordinate system longitude/latitude (wkid 4326) to projected coordinate system Web Mercator (wkid 102100).

Default esri map use Web Mercator as projection system. If you need to convert your coordinates to an other coordinate system you need to use the project method of GeometryService : https://developers.arcgis.com/javascript/3/jsapi/geometryservice-amd.html

Example:

require(["esri/geometry/Point", "esri/tasks/GeometryService", "esri/tasks/ProjectParameters", "esri/SpatialReference", "dojo/domReady!"],
  function(Point, GeometryService, ProjectParameters, SpatialReference) {

    var outSR = "YOUR_OUTPUT_COORDINATE_SYSTEM"; // `wkid {number}`
    var geometryService = new GeometryService("https://utility.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer");
    var inputpoint = new Point({
      longitude: "YOUR_LONGITUDE_INPUT",
      latitude: "YOUR_LATITUDE_INPUT"
    });

    var projectParams = new ProjectParameters();
    projectParams.geometries = [inputpoint];
    projectParams.outSR = new SpatialReference({ wkid: outSR });

    geometryService.project(projectParams, (result) => {
      let outputpoint = result[0]; // outputpoint first element of result array
      console.log("Result x:", outputpoint.x, "y :", outputpoint.y);
    });
  });

Wkid numbers can be found here:

• projected coordinate system: http://resources.arcgis.com/en/help/arcgis-rest-api/index.html#/Projected_coordinate_systems/02r3000000vt000000/

• Geographic coordinate system: http://resources.arcgis.com/en/help/arcgis-rest-api/index.html#/Geographic_coordinate_systems/02r300000105000000/

EDIT

Here is a working example: Plunker