ASP.NET获取真实IP

此方法有问题，还没来得及找问题出在哪儿，估计get那儿肯定是不对了

 1  /// <summary> 
 2     /// 取得客户端真实IP。如果有代理则取第一个非内网地址 
 3     /// </summary> 
 4     public static string IPAddress
 5     {
 6         get
 7         {
 8             string result = String.Empty;
 9 
10             result = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
11             if (result != null && result != String.Empty)
12             {
13                 //可能有代理 
14                 if (result.IndexOf(".") == -1)    //没有“.”肯定是非IPv4格式 
15                     result = null;
16                 else
17                 {
18                     if (result.IndexOf(",") != -1)
19                     {
20                         //有“,”，估计多个代理。取第一个不是内网的IP。 
21                         result = result.Replace(" ", "").Replace("'", "");
22                         string[] temparyip = result.Split(",;".ToCharArray());
23                         for (int i = 0; i < temparyip.Length; i++)
24                         {
25                             if (IsIPAddress(temparyip[i])
26                                 && temparyip[i].Substring(0, 3) != "10."
27                                 && temparyip[i].Substring(0, 7) != "192.168"
28                                 && temparyip[i].Substring(0, 7) != "172.16.")
29                             {
30                                 return temparyip[i];    //找到不是内网的地址 
31                             }
32                         }
33                     }
34                     else if (IsIPAddress(result)) //代理即是IP格式 
35                         return result;
36                     else
37                         result = null;    //代理中的内容 非IP，取IP 
38                 }
39 
40             }
41 
42             string IpAddress = (HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"] != null && HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"] != String.Empty) ? HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"] : HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
43 
44  
45 
46             if (null == result || result == String.Empty)
47                 result = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
48 
49             if (result == null || result == String.Empty)
50                 result = HttpContext.Current.Request.UserHostAddress;
51 
52             return result;
53         }
54     }
55     #region bool IsIPAddress(str1) 判断是否是IP格式
56     /**/
57     /// <summary>
58     /// 判断是否是IP地址格式 0.0.0.0
59     /// </summary>
60     /// <param name="str1">待判断的IP地址</param>
61     /// <returns>true or false</returns>
62     public static bool IsIPAddress(string str1)
63     {
64         if (str1 == null || str1 == string.Empty || str1.Length < 7 || str1.Length > 15) return false;
65 
66         string regformat = @"^\d{1,3}[\.]\d{1,3}[\.]\d{1,3}[\.]\d{1,3}$";
67 
68         Regex regex = new Regex(regformat, RegexOptions.IgnoreCase);
69         return regex.IsMatch(str1);
70     }
71     #endregion
72 
73