【WebAPI】将硬件GPS转换为高德GPS（WGS-84转GCJ-02）

        const string KEY = "这里填写高德WebAPI的KEY，其他KEY例如安卓KEY ，JS KEY都不可以。";

        /// 

        /// 国际标准GPS转换高德GPS
        /// 
        /// 原始经度
        /// 原始纬度
        /// 返回以逗号分割的经纬度组合字符串
        public static string WGS84ToGCJ02(double lon, double lat)
        {
            WebClient server = new WebClient();
            string url = String.Format("http://restapi.amap.com/v3/assistant/coordinate/convert?locations={0},{1}&coordsys=gps&output=json&key={2}", lon, lat, KEY);
            var replyBuffer = server.DownloadData(url);
            var reply = System.Text.Encoding.UTF8.GetString(replyBuffer);
            if (String.IsNullOrEmpty(reply))
                return "";
            JObject result = (JObject)JsonConvert.DeserializeObject(reply);
            if (result["status"].Value() == "1")
            {
                var locations = result["locations"];
                var gps = locations.Value();
                return gps;
            }
            else
                return "";
        }

将硬件原始GPS转换为 高德GPS
var location =WGS84ToGCJ02(120.123212,30.121232);
if(location =="")
   return;
var lon =location.Split(',')[0]; // 获取的经度。
var lat =location.Split(',')[1]; //获取的纬度。