百度地图api定位，根据经纬度显示当前城市名

当前城市：<span id="pro_num">郑州</span>
<div id="allmap"></div>
<script type="text/javascript" src="http://api.map.baidu.com/api?v=2.0&ak=您的密钥"></script>
<script>
// 百度地图API功能
    var map = new BMap.Map("allmap");
    var point = new BMap.Point(116.331398,39.897445);
    map.centerAndZoom(point,12);
//浏览器定位
    var geolocation = new BMap.Geolocation();
    geolocation.getCurrentPosition(function(r){
        if(this.getStatus() == BMAP_STATUS_SUCCESS){
            var mk = new BMap.Marker(r.point);
            map.addOverlay(mk);
            map.panTo(r.point);
            // alert('您的位置：'+r.point.lng+','+r.point.lat);
            $('#lat').val(r.point.lat);//获取到的纬度
            $('#lon').val(r.point.lng);//获取到的经度

            var gc = new BMap.Geocoder();
            var pointAdd = new BMap.Point(r.point.lng, r.point.lat);
            gc.getLocation(pointAdd, function(rs){
                // 百度地图解析城市名
                $('#pro_num').html(rs.addressComponents.city);
                //或者其他信息
                console.log(rs);
            })
        }
        else {
            alert('failed'+this.getStatus());
        }
    },{enableHighAccuracy: true});
    </script>

console.log(rs);打印出来的结果