根据IP获取详细地址,可以用来做用户识别.进入地区站

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;

namespace QianBianWanHua_Lib
{
    ///   <summary>   
    ///   根据IP获取详细国家，省分，城市，地区的详细信息 
    ///   段小勇
    ///   </summary>   
                
    //辅助类，用于保存IP索引信息   
    public class CZ_INDEX_INFO
    {
        public UInt32 IpSet;
        public UInt32 IpEnd;
        public UInt32 Offset;

        public CZ_INDEX_INFO()
        {
            IpSet = 0;
            IpEnd = 0;
            Offset = 0;
        }
    }

    //读取纯真IP数据库类   
    public class AddressWithIP
    {
        protected bool bFilePathInitialized;
        protected string FilePath;
        protected FileStream FileStrm;
        protected UInt32 Index_Set;
        protected UInt32 Index_End;
        protected UInt32 Index_Count;
        protected UInt32 Search_Index_Set;
        protected UInt32 Search_Index_End;
        protected CZ_INDEX_INFO Search_Set;
        protected CZ_INDEX_INFO Search_Mid;
        protected CZ_INDEX_INFO Search_End;

        public AddressWithIP()
        {
            bFilePathInitialized = false;
        }

        public AddressWithIP(string dbFilePath)
        {
            bFilePathInitialized = false;
            SetDbFilePath(dbFilePath);
        }

        //使用二分法查找索引区，初始化查找区间   
        public void Initialize()
        {
            Search_Index_Set = 0;
            Search_Index_End = Index_Count - 1;
        }

        //关闭文件   
        public void Dispose()
        {
            if (bFilePathInitialized)
            {
                bFilePathInitialized = false;
                FileStrm.Close();
                //FileStrm.Dispose();   
            }

        }


        public bool SetDbFilePath(string dbFilePath)
        {
            if (dbFilePath == "")
            {
                return false;
            }

            try
            {
                FileStrm = new FileStream(dbFilePath, FileMode.Open, FileAccess.Read, FileShare.Read);
            }
            catch
            {
                return false;
            }
            //检查文件长度   
            if (FileStrm.Length < 8)
            {
                FileStrm.Close();
                //FileStrm.Dispose();   
                return false;
            }
            //得到第一条索引的绝对偏移和最后一条索引的绝对偏移   
            FileStrm.Seek(0, SeekOrigin.Begin);
            Index_Set = GetUInt32();
            Index_End = GetUInt32();

            //得到总索引条数   
            Index_Count = (Index_End - Index_Set) / 7 + 1;
            bFilePathInitialized = true;

            return true;

        }

        public string GetAddressWithIP(string IPValue)
        {
            if (!bFilePathInitialized)
                return "";

            Initialize();

            UInt32 ip = IPToUInt32(IPValue);

            while (true)
            {

                //首先初始化本轮查找的区间   

                //区间头   
                Search_Set = IndexInfoAtPos(Search_Index_Set);
                //区间尾   
                Search_End = IndexInfoAtPos(Search_Index_End);

                //判断IP是否在区间头内   
                if (ip >= Search_Set.IpSet && ip <= Search_Set.IpEnd)
                    return ReadAddressInfoAtOffset(Search_Set.Offset);


                //判断IP是否在区间尾内   
                if (ip >= Search_End.IpSet && ip <= Search_End.IpEnd)
                    return ReadAddressInfoAtOffset(Search_End.Offset);

                //计算出区间中点   
                Search_Mid = IndexInfoAtPos((Search_Index_End + Search_Index_Set) / 2);

                //判断IP是否在中点   
                if (ip >= Search_Mid.IpSet && ip <= Search_Mid.IpEnd)
                    return ReadAddressInfoAtOffset(Search_Mid.Offset);

                //本轮没有找到，准备下一轮   
                if (ip < Search_Mid.IpSet)
                    //IP比区间中点要小，将区间尾设为现在的中点，将区间缩小1倍。   
                    Search_Index_End = (Search_Index_End + Search_Index_Set) / 2;
                else
                    //IP比区间中点要大，将区间头设为现在的中点，将区间缩小1倍。   
                    Search_Index_Set = (Search_Index_End + Search_Index_Set) / 2;
            }
            return "";

        }

        private string ReadAddressInfoAtOffset(UInt32 Offset)
        {
            string country = "";
            string area = "";
            UInt32 country_Offset = 0;
            byte Tag = 0;
            //跳过4字节，因这4个字节是该索引的IP区间上限。   
            FileStrm.Seek(Offset + 4, SeekOrigin.Begin);

            //读取一个字节，得到描述国家信息的“寻址方式”   
            Tag = GetTag();

            if (Tag == 0x01)
            {

                //模式0x01，表示接下来的3个字节是表示偏移位置   
                FileStrm.Seek(GetOffset(), SeekOrigin.Begin);

                //继续检查“寻址方式”   
                Tag = GetTag();
                if (Tag == 0x02)
                {
                    //模式0x02，表示接下来的3个字节代表国家信息的偏移位置   
                    //先将这个偏移位置保存起来，因为我们要读取它后面的地区信息。   
                    country_Offset = GetOffset();
                    //读取地区信息（注：按照Luma的说明，好像没有这么多种可能性，但在测试过程中好像有些情况没有考虑到，   
                    //所以写了个ReadArea()来读取。   
                    area = ReadArea();
                    //读取国家信息   
                    FileStrm.Seek(country_Offset, SeekOrigin.Begin);
                    country = ReadString();
                }
                else
                {
                    //这种模式说明接下来就是保存的国家和地区信息了，以'

 

调用方法:

 

    protected void Page_Load(object sender, EventArgs e)
    {
        QianBianWanHua_Lib.AddressWithIP _addresswithip = new QianBianWanHua_Lib.AddressWithIP();
        bool _bSucess = false;
        _bSucess = _addresswithip.SetDbFilePath(Server.MapPath(ConfigurationManager.AppSettings["IPDataBaseUrl"]));
        if(_bSucess)
        {
            string _strName = _addresswithip.GetAddressWithIP("211.147.251.220");
            Response.Write(_strName);
        }
        else
        {
            Response.Write("FileError");
        }
    }

 

使用的是"纯真IP数据库类 "每五天更新一次