根据经纬度定位用户所在城市

//根据经纬度定位用户所在城市

　　　　 if (navigator.geolocation){
            navigator.geolocation.getCurrentPosition(showPosition, showErr);
        }
        function showPosition(position){
            //alert(position.coords.latitude+‘,‘+position.coords.longitude);
            // ak = appkey 访问次数流量有限制
            var xy = window.location.protocol.split(‘:‘)[0] === ‘https‘ ? ‘https‘ : ‘http‘;
            $.getJSON(xy+‘://api.map.baidu.com/geocoder/v2/?location=‘+position.coords.latitude+‘,‘+position.coords.longitude+‘&output=json&pois=1&ak=您的ak‘, function(res){
                //addressComponent => {city: "广州市", district: "天河区", province: "广东省", street: "广州大道", street_number: "中922号-之101-128"}
            console.log(res.result.addressComponent.city);
            })
        }
        function showErr(error){
            var result;
            switch(error.code)
            {
                case error.PERMISSION_DENIED:
                    result="User denied the request for Geolocation.";
                    break;
                case error.POSITION_UNAVAILABLE:
                    result="Location information is unavailable.";
                    break;
                case error.TIMEOUT:
                    result="The request to get user location timed out.";
                    break;
                case error.UNKNOWN_ERROR:
                    result="An unknown error occurred.";
                    break;
            }
            alert(result);
        }

//百度API ： http://lbsyun.baidu.com/index.php?title=webapi/guide/webservice-geocoding