C#联机获取公网IP

C#获取IP的方式有很多种，这里通过http://www.ipip.net/这个稳定的在线IP库的来获取公网IP。

 string tempip = "0.0.0.0";
 WebRequest wr = WebRequest.Create("http://www.ipip.net/");
 Stream s = wr.GetResponse().GetResponseStream();
 if (s != null)
 {
     StreamReader sr = new StreamReader(s, Encoding.UTF8);
     string all = sr.ReadToEnd();
     int start = all.IndexOf("您当前的IP：", StringComparison.Ordinal) + ;
     int end = all.IndexOf("<", start, StringComparison.Ordinal);
     tempip = all.Substring(start, end - start);
     sr.Close();
     s.Close();
 }