前几天需要在百度地图上做云图（热图）预警，搜索了一下可以用heatmap实现，但是heatmap只提供了针对谷歌地图的实现，尽管是百度搜索、谷歌搜索齐用，但都得不到解决。没办法，只有自己研究谷歌地图代码，自助者天助之，最终解决。      

• html文件(bmaps.html)代码

• js文件(heatmap-bmaps.js)代码

function HeatmapOverlay(map,cfg){    this._map=map;    this.conf = cfg;    this.heatmap=null;    this.latlngs=[];    this.bounds=null;        }HeatmapOverlay.prototype = new BMap.Overlay(); HeatmapOverlay.prototype.initialize = function(){   var map=this._map; var el = document.createElement("div");   el.style.position = "absolute";   el.style.top = 0; el.style.left = 0; el.style.border = 0; el.style.width = this._map.getSize().width+"px";   el.style.height = this._map.getSize().height+"px"; this.conf.element = el; map.getPanes().markerPane.appendChild(el);     this.heatmap=h337.create(this.conf); this._div = el;     return el;  } HeatmapOverlay.prototype.draw = function(){        var currentBounds = this._map.getBounds();        if (currentBounds.equals(this.bounds)) {      return;    }    this.bounds = currentBounds;        var ne = this._map.pointToOverlayPixel(currentBounds.getNorthEast()),        sw = this._map.pointToOverlayPixel(currentBounds.getSouthWest()),        topY = ne.y,        leftX = sw.x,        h = sw.y - ne.y,        w = ne.x - sw.x;    this.conf.element.style.left = leftX + 'px';    this.conf.element.style.top = topY + 'px';    this.conf.element.style.width = w + 'px';    this.conf.element.style.height = h + 'px';    this.heatmap.store.get("heatmap").resize();           if(this.latlngs.length > 0){        this.heatmap.clear();                var len = this.latlngs.length;            d = {            max: this.heatmap.store.max,            data: []        };        while(len--){            var latlng = this.latlngs[len].latlng;       if(!BMapLib.GeoUtils.isPointInRect(latlng, currentBounds)){
   continue;}        var divPixel = this._map.pointToOverlayPixel(latlng),            screenPixel = new BMap.Pixel(divPixel.x - leftX, divPixel.y - topY);        var roundedPoint = this.pixelTransform(screenPixel);                     d.data.push({             x: roundedPoint.x,            y: roundedPoint.y,            count: this.latlngs[len].c        });        }        this.heatmap.store.setDataSet(d);    }}HeatmapOverlay.prototype.pixelTransform = function(p){    var w = this.heatmap.get("width"),        h = this.heatmap.get("height");    while(p.x < 0){        p.x+=w;    }        while(p.x > w){    p.x-=w;    }            while(p.y < 0){    p.y+=h;    }    while(p.y > h){    p.y-=h;    }    p.x = (p.x >> 0);    p.y = (p.y >> 0);        return p;}HeatmapOverlay.prototype.setDataSet = function(data){    var mapdata = {        max: data.max,        data: []    };    var d = data.data,        dlen = d.length;    this.latlngs = [];       while(dlen--){            var latlng = new BMap.Point(d[dlen].lat, d[dlen].lng);        this.latlngs.push({latlng: latlng, c: d[dlen].count});        var point = this.pixelTransform(this._map.pointToOverlayPixel(latlng));        mapdata.data.push({x: point.x, y: point.y, count: d[dlen].count});    }    this.heatmap.clear();    this.heatmap.store.setDataSet(mapdata);}HeatmapOverlay.prototype.addDataPoint = function(lat, lng, count){    var latlng = new BMap.Point(lat, lng),        point = this.pixelTransform(this._map.pointToOverlayPixel(latlng));        this.heatmap.store.addDataPoint(point.x, point.y, count);    this.latlngs.push({ latlng: latlng, c: count });}HeatmapOverlay.prototype.toggle = function(){    this.heatmap.toggleDisplay();}

效果图如下：