百度地图：两点间距离

 var point1 = new BMap.Point(116.332782, 40.007978);
    var point2 = new BMap.Point(116.332782, 41.007978);
    var distance = map.getDistance(point1, point2);
    var mileage = (distance / 1000).toFixed(2);
    alert("与距离为" + mileage + "公里");