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我正在尝试将地理坐标系转换为 Esri Webmercator，但是当我进行转换时，结果 x 和 y 的值分别为 0000003232112222... 和 00000012665321...。这很奇怪，因为坐标不存在。

var positions = [];
positions.push(x, y);

var g = new esri.geometry.Point(positions);
g = esri.geometry.geographicToWebMercator(g);
x = g.x;
y = g.y;
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2 回答 2

1

您应该尝试模块中的geographicToWebMercator方法esri/geometry/webMercatorUtils。请参阅详细文档。

        //a point in GCS_WGS_1984(wkid is 4326)
        var point = new Point(-118.15, 33.80, new SpatialReference({
            wkid: 4326
        }));

        var pointWebMercator = webMercatorUtils.geographicToWebMercator(point);

        alert("the point in 102100 is ( " + pointWebMercator.x + "," + pointWebMercator.y + " )");

现场演示：

<!DOCTYPE html>
<html>

<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <meta name="viewport" content="initial-scale=1, maximum-scale=1,user-scalable=no" />
    <title>Converting geographic WGS 84 to Web Mercator 102100</title>
    <link rel="stylesheet" href="https://js.arcgis.com/3.20/esri/css/esri.css">
    <style>
        html,
        body,
        #map {
            height: 100%;
            margin: 0;
            padding: 0;
        }
    </style>
    <script src="https://js.arcgis.com/3.20/"></script>
    <script>
        var map;

        require(["esri/map", "esri/geometry/Point", "esri/SpatialReference", "esri/geometry/webMercatorUtils", "dojo/domReady!"], function (Map, Point, SpatialReference, webMercatorUtils) {
            map = new Map("map", {
                basemap: "topo", //For full list of pre-defined basemaps, navigate to http://arcg.is/1JVo6Wd
                center: [-122.45, 37.75], // longitude, latitude
                zoom: 13
            });

            //a point in GCS_WGS_1984(wkid is 4326)
            var point = new Point(-118.15, 33.80, new SpatialReference({
                wkid: 4326
            }));

            var pointWebMercator = webMercatorUtils.geographicToWebMercator(point);

            alert("the point in 102100 is ( " + pointWebMercator.x + "," + pointWebMercator.y + " )");
        });
    </script>
</head>

<body>
    <div id="map"></div>
</body>

</html>

希望它可以帮助你。

于 2017-06-25T00:55:07.317 回答
0

您实际上不必转换纬度/经度即可将点添加到 webmercator 中的底图。

您可以通过几种不同的方式直接使用纬度/经度创建点（API 将在内部进行从地理到 webmercator 的转换）。这从 3.3 版（2013 年 1 月）开始可用。

var point = new Point(-98, 38); // note that longitude(x) comes before the latitude(y).

// or as an array
var point = new Point([-98, 38]);

// or as an object
var point = new Point({latitude: 38, longitude: -98});

https://developers.arcgis.com/javascript/3/jsapi/point-amd.html#point4

于 2017-05-23T06:22:49.353 回答