c#通过ip获取地理信息

/// <summary>
      /// 通过ip得到ip所在地省市（porschev）
      /// </summary>
      /// <param name="ip"></param>
      /// <returns></returns>
      public string getadrbyip(string ip)
      {
          string url = "http://www.cz88.net/ip/?ip=" + ip;
          string regstr = "(?<=<span\\s*id=\\\"cz_addr\\\">).*?(?=</span>)";
          //得到网页源码
          string html = gethtml(url);
          regex reg = new regex(regstr, regexoptions.none);
          match ma = reg.match(html);
          html = ma.value;
          string[] arr = html.split(' ');
          return arr[0];
      }
      /// <summary>
      /// 获取html源码信息(porschev)
      /// </summary>
      /// <param name="url">获取地址</param>
      /// <returns>html源码</returns>
      public string gethtml(string url)
      {
          string str = "";
          try
          {
              uri uri = new uri(url);
              webrequest wr = webrequest.create(uri);
              stream s = wr.getresponse().getresponsestream();
              streamreader sr = new streamreader(s, encoding.default);
              str = sr.readtoend();
          }
          catch (exception e)
          {
          }
          return str;
      }
      /// <summary>
      /// 得到真实ip以及所在地详细信息（porschev）
      /// </summary>
      /// <returns></returns>
      public string getipdetails()
      {
          //设置获取ip地址和国家源码的网址
          string url = "http://www.ip138.com/ips8.asp";
          string regstr = "(?<=<td\\s*align=\\\"center\\\">)[^<]*?(?=<br/><br/></td>)";
          //ip正则
          string ipregstr = "((2[0-4]\\d|25[0-5]|[01]?\\d\\d?)\\.){3}(2[0-4]\\d|25[0-5]|[01]?\\d\\d?)";
          //ip地址
          string ip = string.empty;
          //国家
          string country = string.empty;
          //省市
          string adr = string.empty;
          //得到网页源码
          string html = gethtml(url);
          regex reg = new regex(regstr, regexoptions.none);
          match ma = reg.match(html); html = ma.value;
          regex ipreg = new regex(ipregstr, regexoptions.none);
          ma = ipreg.match(html);
          //得到ip
          ip = ma.value;
          int index = html.lastindexof("：") + 1;
          //得到国家
          country = html.substring(index);
          adr = getadrbyip(ip);
          return "ip：" + ip + " 国家：" + country + " 省市：" + adr;
      }