c#根据ip获取城市地址

用的API是百度、新浪、淘宝：

1、首先是一个检测获取的值是不是中文的方法，因为有的ip只能识别出来某省，而城市名称则为空返回的json里会出现null或undefined。

public static bool HasChinese(string str)
    {
        return Regex.IsMatch(str, @"[u4e00-u9fa5]");
    }

百度的API

/// <summary>
    /// 百度api
    /// </summary>
    /// <returns></returns>
    public static string GetBaiduIp(string ip)
    {
        try
        {
            string cs = "";
            string url = "http://api.map.baidu.com/location/ip?ak=GlfVlFKSc6Y7aSr73IHM3lQI&ip=" + ip;
            WebClient client = new WebClient();
            var buffer = client.DownloadData(url);
            string jsonText = Encoding.UTF8.GetString(buffer);
            JObject jo = JObject.Parse(jsonText);
            var txt = jo["content"]["address_detail"]["city"];
            JToken st = txt;
            string str = st.ToString();
            if (str == "")
            {
                cs = GetCS(ip);
                return cs;

            }
            int s = str.IndexOf('市');
            string css = str.Substring(0, s);
            bool bl = HasChinese(css);

            if (bl)
            {
                cs = css;
            }
            else
            {
                cs = GetCS(ip);
            }

            return cs;
        }
        catch
        {
            return GetIPCitys(ip);
        }

    }

新浪API（这个是直接获取网页源代码，然后抓取）

 /// <summary>
    /// 新浪api
    /// </summary>
    /// <param name="ip"></param>
    /// <returns></returns>
public static string GetCS(string ip)
    {
        try { 
        string url = "http://int.dpool.sina.com.cn/iplookup/iplookup.php?ip=" + ip;
        WebClient MyWebClient = new WebClient();
        MyWebClient.Credentials = CredentialCache.DefaultCredentials;//获取或设置用于向Internet资源的请求进行身份验证的网络凭据
        Byte[] pageData = MyWebClient.DownloadData(url); //从指定网站下载数据
        string stt = Encoding.GetEncoding("GBK").GetString(pageData).Trim();
        return stt.Substring(stt.Length - 2, 2);
        }
        catch
        {
            return "未知";
        }

    }

淘宝API

/// <summary>
    /// 淘宝api
    /// </summary>
    /// <param name="strIP"></param>
    /// <returns></returns>
    public static string GetIPCitys(string strIP)
    {
        try
        {
            string Url = "http://ip.taobao.com/service/getIpInfo.php?ip=" + strIP + "";

            System.Net.WebRequest wReq = System.Net.WebRequest.Create(Url);
            wReq.Timeout = 2000;
            System.Net.WebResponse wResp = wReq.GetResponse();
            System.IO.Stream respStream = wResp.GetResponseStream();
            using (System.IO.StreamReader reader = new System.IO.StreamReader(respStream))
            {
                string jsonText = reader.ReadToEnd();
                JObject ja = (JObject)JsonConvert.DeserializeObject(jsonText);
                if (ja["code"].ToString() == "0")
                {
                    string c = ja["data"]["city"].ToString();
                    int ci = c.IndexOf('市');
                    if (ci != -1)
                    {
                        c = c.Remove(ci, 1);
                    }
                    return c;
                }
                else
                {
                    return "未知";
                }
            }
        }
        catch (Exception)
        {
            return ("未知");
        }
    }