C#根据IP地址查询所属地区实例详解

/// <summary> 
    /// 根据ip 获取物理地址 
    /// </summary> 
    /// <param name="ip">ip地址</param> 
    /// <returns></returns> 
    public static string getipaddress(string ip)
    {
      string url = "http://ip-api.com/json/"+ip+"?lang=zh-cn";
      string result = "";
      webrequest wrt = null;
      webresponse wrp = null;
      try
      {
        wrt = webrequest.create(url);
        wrt.credentials = credentialcache.defaultcredentials;
 
        wrp = wrt.getresponse();
        streamreader sr = new streamreader(wrp.getresponsestream(), encoding.utf8);
        //获取到的是json数据
        string html = sr.readtoend();
 
        //newtonsoft.json读取数据
        jobject obj = jsonconvert.deserializeobject<jobject>(html);
        string city = obj["city"].tostring();
        string province = obj["regionname"].tostring();
        result = city.equals(province) ? city : (province + city);
      }
      catch (exception)
      {
      }
      finally
      {
        if (wrp != null)
          wrp.close();
        if (wrt != null)
          wrt.abort();
      }
      return result;
    }

/// <summary> 
    /// 根据ip 获取物理地址 
    /// </summary> 
    /// <param name="ip">ip地址</param> 
    /// <returns></returns> 
    public static string getstringipaddress(string ip)
    {
      string url = "http://ip.ws.126.net/ipquery?ip="+ip;
      string result="";
      webrequest wrt = null;
      webresponse wrp = null;
      try
      {
        wrt = webrequest.create(url);
        wrt.credentials = credentialcache.defaultcredentials;
 
        wrp = wrt.getresponse();
        streamreader sr = new streamreader(wrp.getresponsestream(), encoding.default);
        //获取到的数据格式：var lo="江苏省", lc="镇江市"; var localaddress={city:"镇江市", province:"江苏省"}
        string html = sr.readtoend();
        string pattern = "{city:\"(?<key1>.*?)\", province:\"(?<key2>.*?)\"}";
        regex regex = new regex(pattern, regexoptions.none);
        match match = regex.match(html);
        string city=match.groups["key1"].value;
        string province=match.groups["key2"].value;
        result = city.equals(province) ? city : (province + city);
      }
      catch (exception)
      {
      }
      finally
      {
        if (wrp != null)
          wrp.close();
        if (wrt != null)
          wrt.abort();
      }
      return result;
    }