内外网用户判断

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Net;
using System.IO;
using System.Text;
using System.Runtime.InteropServices;
using System.Text.RegularExpressions;

/// <summary>
///Common 的摘要说明
/// </summary>
public class Common
{
    public Common()
    {

    }
    //导入判断网络是否连接的 .dll  
    [DllImport("wininet.dll", EntryPoint = "InternetGetConnectedState")]
    /// <summary>
    /// 判断网络状况的方法,返回值true为连接，false为未连接  
    /// </summary>
    /// <returns></returns>
    public extern static bool InternetGetConnectedState(out int conState, int reder);


    /// <summary> 
    /// 取得客户端真实IP。如果有代理则取第一个非内网地址 
    /// by flower.b 
    /// </summary> 
    public static string IPAddress
    {
        get
        {
            string result = String.Empty;

            result = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
            if (result != null && result != String.Empty)
            {
                //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["REMOTE_ADDR"];



            if (null == result || result == String.Empty)
                result = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];

            if (result == null || result == String.Empty)
                result = HttpContext.Current.Request.UserHostAddress;

            return result;
        }
    }


    /// <summary>
    /// 返回用户类型（）
    /// </summary>
    /// <returns></returns>
    public static IPType UserIPType()
    {
        string userIp = IPAddress;

        if (userIp == "127.0.0.1")//本机 (内网功能)
        {
            return IPType.Innner;
        }
        else if (userIp == "10.0.0.1")//内网(内网功能)
        {
            return IPType.Innner;
        }
        else//外网(外网功能)
        {
            return IPType.Out;

        }

    }


    #region bool IsIPAddress(str1) 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 (str1 == null || str1 == string.Empty || str1.Length < 7 || str1.Length > 15) return false;

        string regformat = @"^\d{1,3}[\.]\d{1,3}[\.]\d{1,3}[\.]\d{1,3}$";

        Regex regex = new Regex(regformat, RegexOptions.IgnoreCase);
        return regex.IsMatch(str1);
    }
    #endregion





    /// <summary>
    /// 用户IP类型
    /// </summary>
    public enum IPType
    {
        /// <summary>
        /// 内网用户(含本机用户)
        /// </summary>
        Innner,
        /// <summary>
        /// 外网用户
        /// </summary>
        Out
    }
}

调用

 string url ="";
        //内网用户
        if (Common.UserIPType()==Common.IPType.Innner)
        {
           url= "http://172.16.10.120/xxx";
            PageContext.RegisterStartupScript("window.open('" + url + "','_blank','');");
        }
        else        //外网用户
        {
            url = "http://xxx.example.com.cn/xxx";
            PageContext.RegisterStartupScript("window.open('" + url + "','_blank','');");
        }