利用到天气预报的WebService，代码如下：

 public partial class frmMain : Form
    {
        WeatherWebService we;
        IpAddressSearchWebService we1;

        public frmMain()
        {
            InitializeComponent();
        }

        private void frmMain_Load(object sender, EventArgs e)
        {
            try
            {                
                we = new WeatherWebService();    

                we1 = new IpAddressSearchWebService();
                string locality = we1.getCountryCityByIp(GetIP())[1];
                string city = locality.Substring(locality.IndexOf(‘省‘) + 1, locality.IndexOf(‘市‘) - (locality.IndexOf(‘省‘) + 1));
                WeatherShow(we.getWeatherbyCityName(city));
            }
            catch (System.Exception ex)
            {

            }
        }

        private void WeatherShow(string[] strWeather)
        {
            labelTitle.Text = string.Format(strWeather[1]);       
        }

        public static string GetIP()
        {
            using (var webClient = new WebClient())
            {
                try
                {
                    var temp = webClient.DownloadString("http://iframe.ip138.com/ic.asp");
                    var ip = Regex.Match(temp, @"\[(?<ip>\d+\.\d+\.\d+\.\d+)]").Groups["ip"].Value;
                    return !string.IsNullOrEmpty(ip) ? ip : null;
                }
                catch (Exception ex)
                {
                    return ex.Message;
                }
            }
        }
    }

源代码下载

Winform-根据当前IP获取所在城市名称,布布扣,bubuko.com

Winform-根据当前IP获取所在城市名称