C#获取本机公网IP

 /// <summary>
 /// 获取本机公网IP
 /// </summary>
 /// <returns></returns>
 public static string GetIP_Lan()
 {
     string tempip = "127.0.0.1";
     try
     {
         WebRequest wr = WebRequest.Create("http://www.ip138.com/ip2city.asp");
         Stream s = wr.GetResponse().GetResponseStream();
         StreamReader sr = new StreamReader(s, Encoding.Default);
         string all = sr.ReadToEnd();
         int start = all.IndexOf("[") + ;
         int end = all.IndexOf("]", start);
         tempip = all.Substring(start, end - start);
         sr.Close();
         s.Close();
     }
     catch
     {
     }
     return tempip;
 }