ASP.NET 查询客户端请求IP地址

public class CheckIP  
   {  
       #region 获取浏览器版本号  
  
       /// <summary>  
       /// 获取浏览器版本号  
       /// </summary>  
       /// <returns></returns>  
       public static string GetBrowser()  
       {  
           HttpBrowserCapabilities bc = HttpContext.Current.Request.Browser;  
           return bc.Browser + bc.Version;  
       }  
 
       #endregion  
 
       #region 获取操作系统版本号  
  
       /// <summary>  
       /// 获取操作系统版本号  
       /// </summary>  
       /// <returns></returns>  
       public static string GetOSVersion()  
       {  
           //UserAgent   
           var userAgent = HttpContext.Current.Request.ServerVariables["HTTP_USER_AGENT"];  
  
           var osVersion = "未知";  
  
           if (userAgent.Contains("NT 6.1"))  
           {  
               osVersion = "Windows 7";  
           }  
           else if (userAgent.Contains("NT 6.0"))  
           {  
               osVersion = "Windows Vista/Server 2008";  
           }  
           else if (userAgent.Contains("NT 5.2"))  
           {  
               osVersion = "Windows Server 2003";  
           }  
           else if (userAgent.Contains("NT 5.1"))  
           {  
               osVersion = "Windows XP";  
           }  
           else if (userAgent.Contains("NT 5"))  
           {  
               osVersion = "Windows 2000";  
           }  
           else if (userAgent.Contains("NT 4"))  
           {  
               osVersion = "Windows NT4";  
           }  
           else if (userAgent.Contains("Me"))  
           {  
               osVersion = "Windows Me";  
           }  
           else if (userAgent.Contains("98"))  
           {  
               osVersion = "Windows 98";  
           }  
           else if (userAgent.Contains("95"))  
           {  
               osVersion = "Windows 95";  
           }  
           else if (userAgent.Contains("Mac"))  
           {  
               osVersion = "Mac";  
           }  
           else if (userAgent.Contains("Unix"))  
           {  
               osVersion = "UNIX";  
           }  
           else if (userAgent.Contains("Linux"))  
           {  
               osVersion = "Linux";  
           }  
           else if (userAgent.Contains("SunOS"))  
           {  
               osVersion = "SunOS";  
           }  
           return osVersion;  
       }  
       #endregion  
 
       #region 获取客户端IP地址  
  
       /// <summary>  
       /// 获取客户端IP地址  
       /// </summary>  
       /// <returns></returns>  
       public static string GetIP()  
       {  
           string result = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];  
           if (string.IsNullOrEmpty(result))  
           {  
               result = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];  
           }  
           if (string.IsNullOrEmpty(result))  
           {  
               result = HttpContext.Current.Request.UserHostAddress;  
           }  
           if (string.IsNullOrEmpty(result))  
           {  
               return "0.0.0.0";  
           }  
           return result;  
       }  
 
       #endregion  
 
       #region 取客户端真实IP  
  
       ///  <summary>    
       ///  取得客户端真实IP。如果有代理则取第一个非内网地址    
       ///  </summary>    
       public static string GetIPAddress  
       {  
           get  
           {  
               var result = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];  
               if (!string.IsNullOrEmpty(result))  
               {  
                   //可能有代理    
                   if (result.IndexOf(".") == -1)        //没有“.”肯定是非IPv4格式    
                       result = null;  
                   else  
                   {  
                       if (result.IndexOf(",") != -1)  
                       {  
                           //有“,”，估计多个代理。取第一个不是内网的IP。    
                           result = result.Replace("  ", "").Replace("'", "");  
                           string[] temparyip = result.Split(",;".ToCharArray());  
                           for (int i = 0; i < temparyip.Length; i++)  
                           {  
                               if (IsIPAddress(temparyip[i])  
                                       && temparyip[i].Substring(0, 3) != "10."  
                                       && temparyip[i].Substring(0, 7) != "192.168"  
                                       && temparyip[i].Substring(0, 7) != "172.16.")  
                               {  
                                   return temparyip[i];        //找到不是内网的地址    
                               }  
                           }  
                       }  
                       else if (IsIPAddress(result))  //代理即是IP格式    
                           return result;  
                       else  
                           result = null;        //代理中的内容  非IP，取IP    
                   }  
  
               }  
  
               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["HTTP_X_REAL_IP"];  
  
               if (string.IsNullOrEmpty(result))  
                   result = HttpContext.Current.Request.ServerVariables["HTTP_X_REAL_IP"];  
  
               if (string.IsNullOrEmpty(result))  
                   result = HttpContext.Current.Request.UserHostAddress;  
  
               return result;  
           }  
       }  
 
       #endregion  
 
       #region  判断是否是IP格式  
  
       ///  <summary>  
       ///  判断是否是IP地址格式  0.0.0.0  
       ///  </summary>  
       ///  <param  name="str1">待判断的IP地址</param>  
       ///  <returns>true  or  false</returns>  
       public static bool IsIPAddress(string str1)  
       {  
           if (string.IsNullOrEmpty(str1) || str1.Length < 7 || str1.Length > 15) return false;  
  
           const string regFormat = @"^d{1,3}[.]d{1,3}[.]d{1,3}[.]d{1,3}$";  
  
           var regex = new Regex(regFormat, RegexOptions.IgnoreCase);  
           return regex.IsMatch(str1);  
       }  
 
       #endregion  
 
       #region 获取公网IP  
       /// <summary>  
       /// 获取公网IP  
       /// </summary>  
       /// <returns></returns>  
       public static string GetNetIP()  
       {  
           string tempIP = "";  
           try  
           {  
               System.Net.WebRequest wr = System.Net.WebRequest.Create("http://city.ip138.com/ip2city.asp");  
               System.IO.Stream s = wr.GetResponse().GetResponseStream();  
               System.IO.StreamReader sr = new System.IO.StreamReader(s, System.Text.Encoding.GetEncoding("gb2312"));  
               string all = sr.ReadToEnd(); //读取网站的数据  
  
               int start = all.IndexOf("[") + 1;  
               int end = all.IndexOf("]", start);  
               tempIP = all.Substring(start, end - start);  
               sr.Close();  
               s.Close();  
           }  
           catch  
           {  
               if (System.Net.Dns.GetHostEntry(System.Net.Dns.GetHostName()).AddressList.Length > 1)  
                   tempIP = System.Net.Dns.GetHostEntry(System.Net.Dns.GetHostName()).AddressList[1].ToString();  
               if (string.IsNullOrEmpty(tempIP))  
                   return GetIP();  
           }  
           return tempIP;  
       }  
       #endregion  
   }