前言
之前写过一篇openlayers4版本的地图绘制扇形文章，但是由于是封装一层 js代码写的，很多初学者看起来比较有点吃力，所以本篇文章重新写一篇地图绘制扇形文章，直接基于最新版本openlayers6写的，纯粹html + js + css形式，没有任何封装。
内容概览
1.基于openlayers6实现地图绘制扇形
2.源代码demo下载
效果图如下：
具体实现过程
- html 样式
<html> <head> <meta charset="utf-8"> <title>Using OpenLayers with Webpack</title> <link rel="stylesheet" href="https://openlayers.org/en/latest/css/ol.css" type="text/css"> <style> html, body { margin: 0; height: 100%; } #map { position: absolute; top: 0; bottom: 0; 100%; } .ol-popup { position: absolute; background-color: white; -webkit-filter: drop-shadow(0 1px 4px rgba(0,0,0,0.2)); filter: drop-shadow(0 1px 4px rgba(0,0,0,0.2)); padding: 15px; border-radius: 10px; border: 1px solid #cccccc; bottom: 12px; left: -50px; min- 280px; } .ol-popup:after, .ol-popup:before { top: 100%; border: solid transparent; content: " "; height: 0; 0; position: absolute; pointer-events: none; } .ol-popup:after { border-top-color: white; border- 10px; left: 48px; margin-left: -10px; } .ol-popup:before { border-top-color: #cccccc; border- 11px; left: 48px; margin-left: -11px; } .ol-popup-closer { text-decoration: none; position: absolute; top: 2px; right: 8px; } .ol-popup-closer:after { content: "✖"; } </style> </head> <body> <div id="map"></div> <div id="popup" class="ol-popup"> <a href="#" id="popup-closer" class="ol-popup-closer"></a> <div id="popup-content"></div> </div> <script src="http://libs.baidu.com/jquery/2.1.4/jquery.min.js"></script> <script src="./bundle.js"></script> </body> </html>
- 部分核心代码，完整的见源码demo下载
//扇形模拟数据 var baseStations = { "rows": [{ "baseStationId": 3324020, "baseStationName": "460-00-396906", "longitude": 120.161, "latitude": 30.29683, "azimuth": null, "frequencyPoint": 38950, "bandIndication": 40, "eci": 101607940 }, { "baseStationId": 3324021, "baseStationName": "460-00-396906", "longitude": 120.16039, "latitude": 30.29659, "azimuth": null, "frequencyPoint": 38950, "bandIndication": 40, "eci": 101607941 }, { "baseStationId": 3324022, "baseStationName": "460-00-396906", "longitude": 120.161, "latitude": 30.29683, "azimuth": null, "frequencyPoint": 38950, "bandIndication": 40, "eci": 101607947 }, …… ]} var container = document.getElementById('popup'); var content = document.getElementById('popup-content'); var closer = document.getElementById('popup-closer'); var overlay = new Overlay({ element: container, autoPan: true, autoPanAnimation: { duration: 250 } }); closer.onclick = function() { overlay.setPosition(undefined); closer.blur(); return false; }; var vecsource = new VectorSource(); var veclayer = new VectorLayer({ source: vecsource, style: function(feature) { var info = feature.get("__info"); var bandIndication = info.bandIndication; var text = info.baseStationName; var color = "red"; switch (bandIndication) { case 3: { color = '#9891b3'; break; } case 8: { color = '#90ad36'; break; } case 34: { color = '#b97a57'; break; } case 38: { color = 'red'; break; } case 39: { color = 'green'; break; } case 40: { color = 'blue'; break; } case 41: { color = '#880015'; break; } } return new Style({ stroke: new Stroke({ color: color, 1 }) }); } }); var view = new View({ //projection: 'EPSG:4326', //center: [0, 0], //zoom: 2 //center: [113.90271877, 22.95186415], zoom: 13 }) var map = new Map({ target: 'map', layers: [ new TileLayer({ source: new XYZ({ //url: 'https://{a-c}.tile.openstreetmap.org/{z}/{x}/{y}.png' url: 'http://cache1.arcgisonline.cn/arcgis/rest/services/ChinaOnlineStreetPurplishBlue/MapServer/tile/{z}/{y}/{x}' }) }) ], overlays: [overlay], view: view }); map.addLayer(veclayer); loadbaseStations(baseStations); map.getView().setCenter([13375119.498201383, 3545903.958818198]); map.getView().setZoom(15); //监听地图鼠标事件 map.on('click',function(e) { if (e.dragging) { return; } var feature =map.forEachFeatureAtPixel(e.pixel, function(feature) { return feature; }); if(feature){ var attribute = feature.get('__info'); var winObject=getWinContent(attribute); var centerCoordinates=getCenterCoordinates(feature); showGraphicWin(centerCoordinates,winObject.html,winObject.title); } }) /**获取弹出框html模版 *@attribute **/ function getWinContent(attribute){ var e = attribute; var winHtml=""; var title = attribute.baseStationName; winHtml = "<div style='300px;' id='inforwin_Container'>"+ "<table>"+ "<tr>"+ "<td style='20%'><label style='font-weight:normal;font-size:13px;'>频点:</label></td>"+ "<td><label style='font-weight:normal;font-size:13px;'>"+attribute.frequencyPoint+ "</label></td>"+ "</tr>"+ "<tr>"+ "<td style='20%'><label style='font-weight:normal;font-size:13px;'>eci:</label></td>"+ "<td><label style='font-weight:normal;font-size:13px;'>"+attribute.eci+ "</label></td>"+ "</tr>"+ "<tr>"+ "<td style='20%'><label style='font-weight:normal;font-size:13px;'>经度:</label></td>"+ "<td><label style='font-weight:normal;font-size:13px;'>"+attribute.longitude+ "</label></td>"+ "</tr>"+ "<tr>"+ "<td style='20%'><label style='font-weight:normal;font-size:13px;'>纬度:</label></td>"+ "<td><label style='font-weight:normal;font-size:13px;'>"+attribute.latitude+ "</label></td>"+ "</tr>"+ "</table>"+ "</div>"; return {'html':winHtml,'title':title}; } /** * 弹出气泡窗口 * @centerPoint centerPoint @ 地图跳转中心点 * @html html @ 气泡窗口内容模板 * @title title @ 气泡窗口标题 * **/ function showGraphicWin(centerPoint,html,title){ //DCI.BaseStationsLayer.popover.show(centerPoint, html, title); content.innerHTML = html; overlay.setPosition(centerPoint); } /**获取中心点坐标 * @feature 要素｛ol.feature｝ * return ｛ol.coordinates｝ * */ function getCenterCoordinates(feature){ var coord=new getCenter(feature.getGeometry().getExtent()); return coord; } function clearMap(){ //隐藏气泡窗口 overlay.setPosition(undefined); closer.blur(); } function loadbaseStations(baseStations){ if(baseStations && baseStations.rows.length>0){ var len = baseStations.rows.length; for(var i = 0;i<len;i++){ var record = baseStations.rows[i]; var feature = null; var x = record.longitude; var y = record.latitude; if (isNaN(x) || isNaN(y)) return feature; var geom = toSectorGeometry(record); if (!geom) return feature; record.id = record.id || record.eci; feature = new Feature(); feature.setId(record.id); feature.set("__info", record, true); feature.setGeometry(geom); veclayer.getSource().addFeature(feature); } } } function toSectorGeometry(record){ //频段 var bandIndication = record.bandIndication; var angle, r; var azimuth = record.azimuth; switch (bandIndication) { case 3: { angle = 25; r = 120; break; } case 8: { angle = 20; r = 150; break; } case 34: { angle = 40; r = 100; break; } case 38: { angle = 60; r = 60; break; } case 39: { angle = 50; r = 80; break; } case 40: { //方位角为空 if (isNaN(azimuth)) { angle = 360; r = 25; azimuth = 0; } else { angle = 90; r = 25; } break; } case 41: { angle = 60; r = 60; break; } } var r = r / 111319.49079327358; record["__geomR"] = r; //用于绘制几何的半径 var params = { angle: angle,//夹角 direction: azimuth, x: record.longitude, y: record.latitude, r: r }; //判断不为数字 if (isNaN(params.angle) || isNaN(params.direction) || isNaN(params.x) || isNaN(params.y) || isNaN(params.r)) { return null; } var angles = getAngles(params.angle, params.direction); var rings = getRings([params.x, params.y], params.r, angles[0], angles[1], 30); //坐标系之间转换 if(rings.length>0){ for(var i=0;i<rings.length;i++){ var newCoord= transform(rings[i],'EPSG:4326','EPSG:3857');//由前面坐标系转为后面坐标系坐标 rings[i] = newCoord; } } var polygon = new Polygon([rings]); return polygon; } ……