基于SuperMap iClient for MapboxGL实现等时圈功能

本文主要是介绍基于SuperMap iClient for MapboxGL实现等时圈功能，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

功能介绍

等时圈是指从某点出发，以某种交通方式在特定时间内能到达的距离覆盖的范围。之前在简书上看到过一篇文章，介绍的是基于mapboxgl使用turf去实现等时圈的方法：等时圈实现。
最近在使用超图产品进行学习，看到iClient产品里clasic，for Leaflet,for OpenLayers都有服务区分析这个功能，看了一下是和等时圈的功能是一样的，在mapbox里找了一下并没有在分析中找到这个的范例，但是是有接口存在的，就自己尝试实现了这个功能。

数据准备

这个demo中的数据是用的自己的一份数据，坐标系是4326的，自己定义了两个点去做显示，然后根据这两个点作为服务区分析的中心点，自定义权重值实现服务区分析功能。

代码


<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title data-i18n="resources.title_editFeature"></title>
<style>.editPane {position: absolute;right: 10px;top: 10px;text-align: center;background: #FFF;z-index: 1000;}</style>
</head>
<body style=" margin: 0;overflow: hidden;background: #fff;width: 100%;height:100%;position: absolute;top: 0;">
<div id="map" style="margin:0 auto;width: 100%;height: 100%"></div>
<div>
<div class="panel panel-primary editPane" id="editPane">
<div class='panel-heading'>
<h5 class='panel-title text-center'></h5></div>
<div class='panel-body content'><input type='button' class='btn btn-default' value="添加点" onclick='addPoint()'/>&nbsp;
<input type='button' class='btn btn-default' value="提交" onclick='commit()'/>
</div>
</div>
</div>
<script type="text/javascript" include="bootstrap,widgets.alert" src="../js/include-web.js"></script>
<script type="text/javascript" src="../../dist/mapboxgl/include-mapboxgl.js"></script>
<script>var map, id = [], pointFeature, alertDiv, featureService,url2 = "http:// /rest/networkanalyst/data@data";//因为是涉密的数据所以就把url里相关的信息都删掉了var attribution = "<a href='https://www.mapbox.com/about/maps/' target='_blank'>© Mapbox </a>" +" with <span>© <a href='http://iclient.supermap.io' target='_blank'>SuperMap iClient</a> | </span>" +" Map Data <span>© <a href='http://support.supermap.com.cn/product/iServer.aspx' target='_blank'>SuperMap iServer</a></span> ";map = new mapboxgl.Map({container: 'map', // container idstyle: {"version": 8,"sources": {"raster-tiles": {"attribution": attribution,"type": "raster","tiles": ['http:// /rest/maps/map/zxyTileImage.png?prjCoordSys={"epsgCode":3857}&z={z}&x={x}&y={y}'],"tileSize": 256}},"layers": [{"id": "simple-tiles","type": "raster","source": "raster-tiles","minzoom": 5,"maxzoom": 22}]},center: [116.46 , 40.25 ], zoom:7 // starting zoom});map.addControl(new mapboxgl.NavigationControl(), 'top-left');map.addControl(new mapboxgl.supermap.LogoControl(), 'bottom-right');var findServiceAreasService, parameter, analystParameter, resultSetting;var geojsonPoints = {"type": "FeatureCollection","features": [{"type": "Feature","properties": {"name": "Point1"},"geometry": {"type": "Point","coordinates": [116.39558557938878, 40.221582584846047]}},{"type": "Feature","properties": {"name": "Point2"},"geometry": {"type": "Point","coordinates": [116.27004461982942, 40.173681906076759 ]}}]};function addPoint(){//添加分析的显示中心点map.addSource('geodata', { type: 'geojson', data: geojsonPoints });map.addLayer({'id': 'pointlayer','type': 'circle','source': "geodata","paint": {"circle-radius":5,"circle-color": "#FFFF00","circle-opacity": 1,"circle-stroke-width": 5,"circle-stroke-color": "#007cbf","circle-stroke-opacity":1}});}var geo,feature1,feature2;//只是测试用，所以就只定义了两个点，选取的是两个比较密集区域的节点function commit() {var findServiceAreasService, parameter, analystParameter, resultSetting;var centersArray =[];var point1 = new SuperMap.Geometry.Point(116.39558557938878, 40.221582584846047);var point2 = new SuperMap.Geometry.Point(116.27004461982942, 40.173681906076759);//定义两个分析的点var weightsArray = Array.of(1000,500);centersArray.push(point1);centersArray.push(point2);resultSetting = new SuperMap.TransportationAnalystResultSetting({returnEdgeFeatures: true,returnEdgeGeometry: true,returnEdgeIDs: true,returnNodeFeatures: true,returnNodeGeometry: true,returnNodeIDs: true// returnPathGuides: true,// returnRoutes: true});analystParameter = new SuperMap.TransportationAnalystParameter({resultSetting: resultSetting,weightFieldName: "smLength"});parameter = new SuperMap.FindServiceAreasParameters({centers: centersArray,isAnalyzeById: false,parameter: analystParameter,weights: weightsArray});findServiceAreasService = new mapboxgl.supermap.NetworkAnalystService(url2).findServiceAreas(parameter,requestCallback);}var requestCallback =  function processCompleted(findServiceAreasEventArgs) {//回调函数，处理返回的feature，并通过addP()加载在地图中var result = findServiceAreasEventArgs.result,features = [];var arr1 = findServiceAreasEventArgs.result.serviceAreaList[0].serviceRegion;var arr2 = findServiceAreasEventArgs.result.serviceAreaList[1].serviceRegion;feature1 = new SuperMap.Feature.Vector();feature1.geometry = arr1.geometry;feature2 = new SuperMap.Feature.Vector();feature2.geometry = arr2.geometry;features.push(feature1);features.push(feature2);console.log(features);geo = {"type": "FeatureCollection","features": features};addP();} function addP(){//执行添加分析结果map.addSource('geodata1', { type: 'geojson', data: geo });map.addLayer({'id': 'polayer','type': 'fill','source': "geodata1","paint": {"fill-color": "red","fill-opacity": 0.5}});}
</script>
</body>
</html>

最终结果

在这里插入图片描述

总结

一开始使用的是3857的数据，但是发现需要对传入的数值做坐标转换所以相对来说比较麻烦，就尝试了用4326的数据，总体来说效果没有用mapboxgl和turf去做效果更好，毕竟人家是官方出的效果，从直观视觉上来说有一个颜色的渐变更美观，但是实际的效果、最终的目的还是一致的，就是显示某段时间内可以到达的距离。
附上mapbox官方的效果图，还是挺好看的
mapbox的演示效果