百度地圖添加 覆蓋物

//添加 一個 覆蓋物
var point = new BMap.Point(116.301061, 40.061642);
var marker = new BMap.Marker(point);  
map.addOverlay(marker);

//添加多個 覆蓋物
var polygon_nc = new BMap.Polygon([
    new BMap.Point(116.301061, 40.061642)
], {strokeColor:"red",fillColor:"red",fillColorOpacity:"0.4", strokeWeight:2, strokeOpacity:0.3});
   
map.addOverlay(polygon_nc);