C#获取真实IP地址实现方法

本文实例讲述了c#获取真实ip地址实现方法，分享给大家供大家参考。具体实现方法如下：

通常来说，大家获取用户ip地址常用的方法是：

string ipaddress = "";

if((httpcontext.current.request.servervariables["http_x_forwarded_for"]!=null
&& httpcontext.current.request.servervariables["http_x_forwarded_for"] !=string.empty) )
{
        ipaddress=httpcontext.current.request.servervariables["http_x_forwarded_for"] ;
}
else
{
        httpcontext.current.request.servervariables["remote_addr"];
}

事实上，上面的代码只试用与用户只使用了1层代理，如果用户有2层，3层http_x_forwarded_for 的值是："本机真实ip,1层代理ip,2层代理ip,....." ，如果这个时候你的数据中保存ip字段的长度很小（15个字节），数据库就报错了。

实际应用中，因为使用多层透明代理的情况比较少，所以这种用户并不多。

获取用户真实ip的方法

using system;
using system.data;
using system.configuration;
using system.web;
using system.web.security;
using system.web.ui;
using system.web.ui.webcontrols;
using system.web.ui.webcontrols.webparts;
using system.web.ui.htmlcontrols;
using system.text.regularexpressions;
namespace common
{
    /// <summary>
    /// ipaddress 的摘要说明
    /// </summary>
public class ipaddress : system.web.ui.page
{

    public static int64 todenaryip ( string ip )
    {
        int64 _int64 = 0;
        string _ip = ip;
        if ( _ip.lastindexof ( "." ) > -1 )
        {
            string[] _iparray = _ip.split ( '.' );

            _int64 = int64.parse ( _iparray.getvalue ( 0 ).tostring() ) * 256 * 256 * 256 + int64.parse ( _iparray.getvalue ( 1 ).tostring() ) * 256 * 256 + int64.parse ( _iparray.getvalue ( 2 ).tostring() ) * 256 + int64.parse ( _iparray.getvalue ( 3 ).tostring() ) - 1;
        }
        return _int64;
    }

    /// <summary>
    /// /ip十进制
    /// </summary>
    public static int64 denaryip
    {
        get {
            int64 _int64 = 0;

            string _ip = ip;
            if ( _ip.lastindexof ( "." ) > -1 )
            {
                string[] _iparray= _ip.split ( '.' );

                _int64 = int64.parse ( _iparray.getvalue ( 0 ).tostring() ) * 256 * 256 * 256 + int64.parse ( _iparray.getvalue ( 1 ).tostring() ) * 256 * 256 + int64.parse ( _iparray.getvalue ( 2 ).tostring() ) * 256 + int64.parse ( _iparray.getvalue ( 3 ).tostring() )-1;
            }
            return _int64;
        }
    }

    public static string ip
    {
        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;
        }
    }

     //是否ip格式
    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 );
    }
}
}

希望本文所述对大家的c#程序设计有所帮助。