根据ip获取用户地理位置

各大网站都提供根据ip获取用户地理位置信息，这里以新浪的接口为例子

接口地址为：http://int.dpool.sina.com.cn/iplookup/iplookup.php?format=js&ip=218.18.171.146

代码：

        #region 根据ip获取地点
        /// 获取Ip归属地
        /// </summary>
        /// <param name="ip">ip</param>
        /// <returns>归属地</returns>
        public static string GetIpAddress(string ip)
        {
            JavaScriptSerializer Jss = new JavaScriptSerializer();
            //http://int.dpool.sina.com.cn/iplookup/iplookup.php?format=js&ip=218.18.171.146 调用新浪的接口
            //var remote_ip_info = {"ret":1,"start":-1,"end":-1,"country":"u4e2du56fd","province":"u5e7fu4e1c","city":"u6df1u5733","district":"","isp":"","type":"","desc":""};
            string address = string.Empty;
            try
            {
                string reText = WebRequestPostOrGet("http://int.dpool.sina.com.cn/iplookup/iplookup.php?format=js&ip="+ip, "");
                reText = reText.Split('=')[1].Split(';')[0].Trim();
                Dictionary<string, object> DicText = (Dictionary<string, object>)Jss.DeserializeObject(reText);
                address = DicText["city"].ToString();
            }
            catch { }
            return address;
        }
        #endregion

其中WebRequestPostOrGet方法:

        #region Post/Get提交调用抓取
        /// <summary>
        /// Post/get 提交调用抓取
        /// </summary>
        /// <param name="url">提交地址</param>
        /// <param name="param">参数</param>
        /// <returns>string</returns>
        public static string WebRequestPostOrGet(string sUrl, string sParam)
        {
            byte[] bt = System.Text.Encoding.UTF8.GetBytes(sParam);

            Uri uriurl = new Uri(sUrl);
            HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(uriurl);//HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(url + (url.IndexOf("?") > -1 ? "" : "?") + param);
            req.Method = "Post";
            req.Timeout = 120 * 1000;
            req.ContentType = "application/x-www-form-urlencoded;";
            req.ContentLength = bt.Length;

            using (Stream reqStream = req.GetRequestStream())//using 使用可以释放using段内的内存
            {
                reqStream.Write(bt, 0, bt.Length);
                reqStream.Flush();
            }
            try
            {
                using (WebResponse res = req.GetResponse())
                {
                    //在这里对接收到的页面内容进行处理 

                    Stream resStream = res.GetResponseStream();

                    StreamReader resStreamReader = new StreamReader(resStream, System.Text.Encoding.UTF8);

                    string resLine;

                    System.Text.StringBuilder resStringBuilder = new System.Text.StringBuilder();

                    while ((resLine = resStreamReader.ReadLine()) != null)
                    {
                        resStringBuilder.Append(resLine + System.Environment.NewLine);
                    }

                    resStream.Close();
                    resStreamReader.Close();

                    return resStringBuilder.ToString();
                }
            }
            catch (Exception ex)
            {
                return ex.Message;//url错误时候回报错
            }
        }
        #endregion Post/Get提交调用抓取