ip对应的区域查询(asp.net版)

源代码是一个类

IP的数据文件是从网上下载的，大家只要随便搜索下就有一大把

调用方式 Response.Write(IPSearch.GetAddressWithIP("222.221.164.172"));

http://www.leiyang.ccoo.cn/blog/article.asp?id=451104

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.IO;
/// <summary>
/// IPSearch 的摘要说明
/// </summary>
public class IPSearch
{
     private static object lockHelper = new object();

static PHCZIP pcz = new PHCZIP(); static string filePath = ""; static bool fileIsExsit = true; static IPSearch()
    {
        filePath = HttpContext.Current.Server.MapPath("~/ipdata/QQWry.Dat");
        pcz.SetDbFilePath(filePath);
    } /// 
    /// 返回IP查找结果
    /// 
    /// 要查找的IP地址
    /// 
    public static string GetAddressWithIP(string IPValue)
    {
        lock (lockHelper)
        {
            string result = pcz.GetAddressWithIP(IPValue.Trim()); if (fileIsExsit)
            {
                if (result.IndexOf("IANA") >= 0)
                {
                    return "";
                }
                else
                {
                    return result;
                }
            }
            else
            {
                return null;
            }
        }
    } /// 
    /// 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 PHCZIP
    {
        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 PHCZIP()
        {
            bFilePathInitialized = false;
        } public PHCZIP(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'\0'代表结束。
                    FileStrm.Seek(-1, SeekOrigin.Current);
                    country = ReadString();
                    area = ReadArea();

                }
            }

else if (Tag == 0x02)
            {
                //模式0x02，说明国家信息是一个偏移位置
                country_Offset = GetOffset();
                //先读取地区信息
                area = ReadArea();
                //读取国家信息
                FileStrm.Seek(country_Offset, SeekOrigin.Begin);
                country = ReadString();
            }
            else
            {
                //这种模式最简单了，直接读取国家和地区就OK了
                FileStrm.Seek(-1, SeekOrigin.Current);
                country = ReadString();
                area = ReadArea();

            }

string Address = country + " " + area;
            return Address;

        }

private UInt32 GetOffset()
        {
            byte[] TempByte4 = new byte[4];
            TempByte4[0] = (byte)FileStrm.ReadByte();
            TempByte4[1] = (byte)FileStrm.ReadByte();
            TempByte4[2] = (byte)FileStrm.ReadByte();
            TempByte4[3] = 0;
            return BitConverter.ToUInt32(TempByte4, 0);
        } protected string ReadArea()
        {
            byte Tag = GetTag(); if (Tag == 0x01 || Tag == 0x02)
            {
                FileStrm.Seek(GetOffset(), SeekOrigin.Begin);
                return ReadString();
            }
            else
            {
                FileStrm.Seek(-1, SeekOrigin.Current);
                return ReadString();
            }
        } protected string ReadString()
        {
            UInt32 Offset = 0;
            byte[] TempByteArray = new byte[256];
            TempByteArray[Offset] = (byte)FileStrm.ReadByte();
            while (TempByteArray[Offset] != 0x00)
            {
                Offset += 1;
                TempByteArray[Offset] = (byte)FileStrm.ReadByte();
            }
            return System.Text.Encoding.Default.GetString(TempByteArray).TrimEnd('\0');
        } protected byte GetTag()
        {
            return (byte)FileStrm.ReadByte();
        } protected CZ_INDEX_INFO IndexInfoAtPos(UInt32 Index_Pos)
        {
            CZ_INDEX_INFO Index_Info = new CZ_INDEX_INFO();
            //根据索引编号计算出在文件中在偏移位置
            FileStrm.Seek(Index_Set + 7 * Index_Pos, SeekOrigin.Begin);
            Index_Info.IpSet = GetUInt32();
            Index_Info.Offset = GetOffset();
            FileStrm.Seek(Index_Info.Offset, SeekOrigin.Begin);
            Index_Info.IpEnd = GetUInt32(); return Index_Info;
        } /// 
        /// 从IP转换为Int32
        /// 
        /// 
        /// 
        public UInt32 IPToUInt32(string IpValue)
        {
            string[] IpByte = IpValue.Split('.');
            Int32 nUpperBound = IpByte.GetUpperBound(0);
            if (nUpperBound != 3)
            {
                IpByte = new string[4];
                for (Int32 i = 1; i <= 3 - nUpperBound; i++)
                    IpByte[nUpperBound + i] = "0";
            } byte[] TempByte4 = new byte[4];
            for (Int32 i = 0; i <= 3; i++)
            {
                //'如果是.Net 2.0可以支持TryParse。
                //'If Not (Byte.TryParse(IpByte(i), TempByte4(3 - i))) Then
                //'    TempByte4(3 - i) = &H0
                //'End If
                if (IsNumeric(IpByte[i]))
                    TempByte4[3 - i] = (byte)(Convert.ToInt32(IpByte[i]) & 0xff);
            } return BitConverter.ToUInt32(TempByte4, 0);
        } /// 
        /// 判断是否为数字
        /// 
        /// 待判断字符串
        /// 
        protected bool IsNumeric(string str)
        {
            if (str != null && System.Text.RegularExpressions.Regex.IsMatch(str, @"^-?\d+$"))
                return true;
            else
                return false;
        } protected UInt32 GetUInt32()
        {
            byte[] TempByte4 = new byte[4];
            FileStrm.Read(TempByte4, 0, 4);
            return BitConverter.ToUInt32(TempByte4, 0);
        }
    }
}