高德地图1.点聚合 2.放大到最大级别后没办法继续显示（点距离过近，或是同一个经纬度）

1.引用
<script type="text/javascript" src="https://webapi.amap.com/maps?v=1.4.15&key=你申请的key&plugin=AMap.MouseTool,AMap.MarkerClusterer"></script>


2.使用

window.showAllPoint = function(allMarkers) {
        overlayGroups = []; //清空覆盖物群组集合
        markers = []; //清空点的集合
        polyline = null; //清空线标记
        polyGon = null; //清空面标记
        for(var i = 0; i < allMarkers.length; i++) {
            var point = eval(allMarkers[i].lnglat);
            var radius = parseFloat(allMarkers[i].radius); //圆半径 
            //如果是点标记
            if(allMarkers[i].types == 1) {
                //创建点实例
                marker = new AMap.Marker({
                    position: new AMap.LngLat(point[0], point[1]),
                    title: allMarkers[i].name,
                    map: map,
                    icon: allMarkers[i].icon
                });
                if(nowpage == 'gdiframe')
                    marker.content = setInfoContent(allMarkers[i]);
                marker.on('click', markerClick);

                markers.push(marker);
                // 创建覆盖物群组，并将 marker 传给 OverlayGroup
                //overlayGroups = new AMap.OverlayGroup(markers);
                // 添加覆盖物群组
                //map.add(overlayGroups);
                
            }
            //如果是线标记 
            else if(allMarkers[i].types == 2) {
                //创建线实例
                polyline = new AMap.Polyline({
                    path: point,
                    strokeColor: allMarkers[i].color || allMarkers[i].backgrse || "red",
                    strokeOpacity: 1,
                    strokeWeight: 2,
                    strokeStyle: 'solid',
                    strokeDasharray: [10, 5],
                    geodesic: true
                });
                polyline.setMap(map);
                if(nowpage == 'gdiframe')
                    polyline.content = setInfoContent(allMarkers[i]);
                polyline.on('click', lineOrFaceClick);

            }

            //如果是面/矩形标记
            else if(allMarkers[i].types == 3 || (allMarkers[i].types == 4)) {
                //创建面实例
                polyGon = new AMap.Polygon({
                    path: point,
                    map: map,
                    strokeColor: allMarkers[i].color || allMarkers[i].backgrse || "red",
                    strokeOpacity: 1,
                    strokeWeight: 2,
                    strokeStyle: 'solid',
                    strokeDasharray: [10, 5],
                    fillColor: allMarkers[i].color || allMarkers[i].backgrse || "red",
                    fillOpacity: 0.2,
                    geodesic: true
                })
                if(nowpage == 'gdiframe')
                    polyGon.content = setInfoContent(allMarkers[i]);
                polyGon.on('click', lineOrFaceClick);
            }
            //如果是圆形标记
            else if(allMarkers[i].types == 5) {
                //创建圆实例
                polyGon = new AMap.Circle({
                    center: point,
                    radius: radius,
                    map: map,
                    strokeColor: allMarkers[i].color || allMarkers[i].backgrse || "red",
                    strokeOpacity: 1,
                    strokeWeight: 2,
                    strokeStyle: 'solid',
                    strokeDasharray: [10, 5],
                    fillColor: allMarkers[i].color || allMarkers[i].backgrse || "red",
                    fillOpacity: 0.2,
                    geodesic: true
                })
                if(nowpage == 'gdiframe')
                    polyGon.content = setInfoContent(allMarkers[i]);
                polyGon.on('click', lineOrFaceClick);
            }
            
        }
        cluster = new AMap.MarkerClusterer(map, markers, {gridSize: 80});//点聚合
　　　　

// 获取地图的缩放级别，如果级别已经是最高，那么点击后，显示聚合点内的点信息
cluster.on('click',function(e,markers){
if(map.getZoom() == 18){
var itemsContent = "";
e.markers.forEach(function (item, index) {
itemsContent += item.content;
// console.log(itemsContent);
});
e.markers.forEach(function (item, index) {
infoWindow.setContent(itemsContent);
infoWindow.open(map, item.getPosition());
});
}

})

        map.setFitView(); 
    }