arcgis for jsapi 4.10繪製熱力圖
摘要：
版權宣告：本文為博主原屙文章，喜歡你就擔走。 https://blog.csdn.net/leftfist/article/details/87189002
arcgis for jsapi 從 3 變到 4 之後，變化巨大，原先網路上的許多例子，好像都過時了。比如echart與a...
版權宣告：本文為博主原屙文章，喜歡你就擔走。 https://blog.csdn.net/leftfist/article/details/87189002
arcgis for jsapi 從 3 變到 4 之後，變化巨大，原先網路上的許多例子，好像都過時了。比如echart與arcgis結合，都是for 3.x的,4時代就不行了。
熱力圖也一樣。
現在俺給個例子，不依賴於arcgis伺服器，直接渲染出來：
原理是繪製，繪製在FeatureLayer裡。怎麼繪製呢？原來熱力圖有個專門的渲染器：HeatmapRenderer，將樣式賦給該渲染器，然後渲染器、點資料等參與FeatureLayer的構造，就可以了。
<!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>heatMap</title>
<link rel="stylesheet" type="text/css" href="http://192.168.0.211/pubzy/arcgis_js_api/4.10/esri/css/main.css" />
<style>
html, body, #map {
height: 100%;
margin: 0;
padding: 0;
}
</style>
<script src="http://192.168.0.211/pubzy/media/js/jquery-1.11.1.min.js" type="text/javascript"></script>
<script src="http://192.168.0.211/pubzy/arcgis_js_api/4.10/init.js"></script>
</head>
<body>
<div id="map"></div>
</body>
<script>
require(["esri/map",
"esri/views/MapView",
"esri/Basemap",
"esri/geometry/Extent",
"esri/layers/TileLayer",
"esri/layers/FeatureLayer",
"esri/renderers/HeatmapRenderer",
"dojo/domReady!"], function (Map,
MapView,
BaseMap,
Extent,
TileLayer,
FeatureLayer,
HeatmapRenderer) {
let map, view;
(function () {//載入底圖等
map = new Map({
basemap: getBaseMap({
"title": "影像圖",
"thumbnailUrl": "images/map/影像圖.gif",
"type": "tile",
"layer": "http://192.168.0.206:6080/arcgis/rest/services/HNJCZS/HNJCZSYXT/MapServer"
}),
});
view = new MapView({
container: "map",
map: map,
extent: new Extent({
"xmin": 105,
"ymin": 18,
"xmax": 115,
"ymax": 20,
"spatialReference": { "wkid": 4326 }
}),
});
view.ui._removeComponents(["attribution"]);
})();
function getBaseMap(basemapcof) {
let baselayer = new TileLayer({
url: basemapcof.layer,
});
return new BaseMap({
baseLayers: baselayer,
title: basemapcof.title,
thumbnailUrl: "../" + basemapcof.thumbnailUrl,
});
}
var heatmapRenderer = new HeatmapRenderer({//設定渲染器
colorStops: [{ ratio: 0.4, color: "rgba(0, 255, 0, 0)" },
{ ratio: 0.75, color: "rgba(255, 140, 0, 1)" },
{ ratio: 0.9, color: "rgba(255, 0,0, 1)" }],
blurRadius: 8,
maxPixelIntensity: 230,
minPixelIntensity: 10
});
var heatDataUrl = "data/heatJson.json";
$.getJSON(heatDataUrl,{},function(data,textStatus,jqXHR){//讀取資料，設定點資料集
var features = [];
for (var i = 0; i < data.heatData.length; i++) {
var x = data.heatData[i].lng;
var y = data.heatData[i].lat;
features.push({
geometry: {
type: "point",
x: x,
y: y
},
attributes: {
ObjectID: i,//重要！！！
}
});
}
var featureLayer = new FeatureLayer({
source: features,//點資料集
title: "熱力圖",
objectIdField: "ObjectID",//重要！！！
renderer: heatmapRenderer//渲染器
});
map.add(featureLayer);
});
});
</script>
</html>
熱力圖有個專有的名詞：HeatMap，可以用這個單詞去搜。
參考資料：
arcgis js api:熱力圖arcgis for jsapi官網上有兩個例子，一個似乎是直接展示圖層，一個是依賴於CSVLayer，好像挺複雜。
https://developers.arcgis.com/javascript/latest/sample-code/visualization-heatmap-scale/index.html
https://developers.arcgis.com/javascript/latest/sample-code/visualization-heatmap/index.html