百度地圖圓形覆蓋物半徑設置

最近項目開發有這樣一項需求，具體效果如圖：

主要代碼設置：

// 百度地圖API功能
var map = new BMap.Map("allmap");               // 創建Map實例
var mPoint = new BMap.Point(116.404, 39.915); 
map.enableScrollWheelZoom();
map.centerAndZoom(mPoint,15);
var circle = new BMap.Circle(mPoint,1000,{fillColor:"blue", strokeWeight: 1 ,fillOpacity: 0.3, strokeOpacity: 0.3,enableEditing:true});
map.addOverlay(circle);
if (mPoint != null) {
circle.addEventListener("lineupdate", function (e) {
console.log(circle.getRadius()); //返回圓形覆蓋物的半徑
});
}
var local = new BMap.LocalSearch(map, {renderOptions: {map: map, autoViewport: false}});
local.searchNearby('餐館',mPoint,1000);