javascript如何写热点图

在gis中，你如果用js来写热点图不借助后台怎么搞，as的话比较容易有相应的类库甚至官方都有。而且用js不借助arcgis发布rest服务，（注：热点图可以借助服务的形式发布，arcgis for javascript有相应的api支持的），这个时候就比较麻烦了，首先说明下热点图是啥？

热点图是以点的形式展示，通过补全周边变化颜色也会相应的调整渐变，类似于足球某个人的运动范围那种，我找了下有个heapmap可以实现heapmap.js和heapmap-arcgis.js

因为arcigs for javascript api 是以dojo为基础写的，所以加载类库方式以下

SEOnLoad: true

};

写了工具类去使用这个类库

var heatLayer;

var graphicLayer;

var polygonTemp;

var queryVo= new QueryVO();

var ajaxTool;

var locateParameter = new LocateParameter();

var symbolTool;

var isMouseInfo = true;

//查询社区的url来覆盖人口信息
var paramBackFun;
function renderQuery(queryVo1,polygon,roundFlag,paramBackFun1)
{
paramBackFun = paramBackFun1;
var layerName = queryVo1.layerName;
graphicLayer.clear();
var url = locateParameter.getUrl(layerName);
if(url != "")
{
var querytask = new esri.tasks.QueryTask(url);
var query = new esri.tasks.Query();

if(layerName != "shi")
{
query.geometry = polygon;
}
else
{
query.where = "FID >= 0"
}
query.returnGeometry = true;
query.outSpatialReference = map.spatialReference;
if(roundFlag == "false")
{
query.spatialRelationship = esri.tasks.Query.SPATIAL_REL_CONTAINS;
}
query.outFields = ["*"];
querytask.execute(query,handle);
}
}

function handle(idResults)
{
graphicLayer.clear();

var param = new Object();
param.codearr = [];
for (var i = 0,il = idResults.features.length; i < il; i++)
{
var idResult = idResults.features[i];

var polygon = idResult.geometry;

var gra = new esri.Graphic(polygon);

var attributes = idResult.attributes;

param.codearr[i] = attributes[locateParameter.getCodeName(queryVo.layerName)];

var graattribute = new Object();
graattribute["code"] = attributes[locateParameter.getCodeName(queryVo.layerName)];
gra.setAttributes(graattribute);
gra.setSymbol(symbolTool.getSymbol("heat"));
graphicLayer.add(gra);
}
paramBackFun(param);

}

//查询java后台组织json参数
function ajaxQuery(param)
{
param.startDate = queryVo.startDate;
param.endDate = queryVo.endDate;
param.layerName = queryVo.layerName;
param.tjfs = queryVo.tjfs;
var str = JSON.stringify(param);

//alert("ajaxQuery-param: "+str);
//--------------------------------------测试环境用
ajaxTool.getLiuDongData1(str,ajaxBack);
//-------------------------------------

//--------------------------------------真实环境用
// ajaxTool.getLiuDongData(str,ajaxBack);
//-------------------------------------
}

function ajaxBack(obj,num1)
{
//组装 map对象便于遍历graphic
if('2'==queryVo.tjfs){
alert("时间段");
var arr = obj.codearr;

}else{
var arr = obj.codearr;
var mapobj = new Object();
for(var i = 0,l = arr.length; i < l; i++)
{
var arrobj = arr[i];
mapobj[arrobj.CODE] = arrobj;
//alert("ajaxBack: "+arrobj.CODE);
}

//--------------------------------------真实环境用
//var graarr = graphicLayer.graphics;
//var dataarr = [];
//for(var j = 0,m = graarr.length; j < m; j++)
//{
// var gra = graarr[j];
// var codeValue = gra.attributes["code"];
// // 暂时码值转换
// var codeobj;
// if("shi"==queryVo.layerName){
// //alert(changeAreaCode(codeValue));
// codeobj = mapobj[changeAreaCode(codeValue)];
// }else{
// codeobj = mapobj[codeValue];
// }
// //alert("codeValue: "+codeValue);
// if(codeobj!=null){
// var pcount = codeobj.PCOUNT;
// var point = gra.geometry.getCentroid();
// var feobj = {
// attributes: {count:Number(pcount)},// geometry: {
// spatialReference: map.spatialReference,// type: "point",// x: point.x,// y: point.y
//
// }
// }
// dataarr.push(feobj);
// }
// gra.attributes["codeVaue"] = codeobj;
//}
//-------------------------------------

//--------------------------------------测试环境用
var graarr = graphicLayer.graphics;
var dataarr = [];
var pcountnum = 0.1;
for(var j = 0,m = graarr.length; j < m; j++)
{
var gra = graarr[j];
var codeValue = gra.attributes["code"];
var codeobj = mapobj["440304008001"];
var pcount = pcountnum;
var point = gra.geometry.getCentroid();
var feobj = {
attributes: {count:Number(pcount)},geometry: {
spatialReference: map.spatialReference,type: "point",x: point.x,y: point.y

   }

  }
  if(num1 == undefined)
  {
   num1 = 0.01
  }
  pcountnum = pcountnum + num1;
  dataarr.push(feobj);

  gra.attributes["codeVaue"] = codeobj;
 }

//-------------------------------------

heatLayer.setData(dataarr);
}
}

/**

外界返回鼠标移动查询填充图层
@returns {}
/
this.getHeatLocateLayer = function()
{
return graphicLayer;
}

/**

外界返回热点图层
@returns {}
/
this.getHeatlayer = function()
{
return heatLayer;
}

/**

初始化热点图
@param healayerdiv 主页heatlayer div的id
@param map1
*/
this.init = function initHeatLayer(healayerdiv,map1)
{
map = map1;
heatLayer = new HeatmapLayer({
config: {
"useLocalMaximum": true,"radius": 40,"gradient": {
0.45: "rgb(000,000,255)",0.55: "rgb(000,255,0.65: "rgb(000,000)",0.95: "rgb(255,1.00: "rgb(255,000)"
}
},"map": map,"domNodeId": healayerdiv,"opacity": 0.85
});

graphicLayer = new esri.layers.GraphicsLayer();
map.addLayer(heatLayer);
map.addLayer(graphicLayer);

ajaxTool = new AjaxTool();
symbolTool = new SymbolTool();

// map.resize();

}

this.ajaxBackFun= function(obj,num1)
{
ajaxBack(obj,num1);
}

/**

根据查询数据渲染热点图
现在可能是固定死的xml，下次转json 可能要有参数以后定
*/
this.addRender = function(queryVo1,polygon)
{
addRenderFun(queryVo1,ajaxQuery)

}

//简化方法类增加回调
function addRenderFun(queryVo1,paramBackFun1)
{
polygonTemp = polygon;
queryVo = queryVo1;

renderQuery(queryVo,"false",paramBackFun1);
}

/**

@param queryVo1
@param polygon
@param paramBackFun1
*/

this.addRenderCallBack = function(queryVo1,paramBackFun1)
{
addRenderFun(queryVo1,paramBackFun1);
}

/**

清除热点图的数据
*/
this.clearHeatLayer = function()
{
heatLayer.clearData();
}

function changeAreaCode(code){
var resuCode="";
var areaCode = ["440305","440326","440306","440309","440308","440304","440303","440327","440317","440307"];
var mapCode = ["440305002","440306007","440306001","440306012","440308001","440304003","440303005","440307012","440307009","440307006"];
for(i=0;i<areaCode.length;i++){
if(code==mapCode[i]){
resuCode = areaCode[i];
break;
}
}
return resuCode;
}

}

以上就是为大家分享的如何实现热点图的关键代码，希望对大家的学习有所帮助。

javascript如何写热点图

猜你在找的JavaScript相关文章