读大学时写的代码，不够优雅，凑合能用，现共享出来方便有此需求的朋友。
首先要下载纯真IP数据库，然后在代码中指定数据库文件的路径，传入一个IP即可返回其地理位置，请参考Main函数。
- using System;
- using System.Collections.Generic;
- using System.Text;
- using System.IO;
- namespace 纯真IP数据库研究
- {
- ///<summary>
- /// 提供从纯真IP数据库搜索IP信息的方法；
- ///</summary>
- public class IPSearch
- {
- FileStream ipFile;
- long ip;
- string ipfilePath;
- ///<summary>
- /// 构造函数
- ///</summary>
- ///<param name="ipfilePath">纯真IP数据库路径</param>
- public IPSearch(string ipfilePath)
- {
- this.ipfilePath = ipfilePath;
- }
- //测试
- static void Main(string[] args)
- {
- string ipfilePath = @"C:\Documents and Settings\Daode\桌面\qqwry\QQWry.dat";
- IPSearch ipSearch = new IPSearch(ipfilePath);
- string ip = "72.51.27.51";
- IPSearch.IPLocation loc = ipSearch.GetIPLocation(ip);
- Console.WriteLine("你查的ip是：{0} 地理位置：{1} {2}", ip, loc.country, loc.area);
- Console.ReadKey();
- }
- ///<summary>
- /// 地理位置,包括国家和地区
- ///</summary>
- public struct IPLocation
- {
- public string country, area;
- }
- ///<summary>
- /// 获取指定IP所在地理位置
- ///</summary>
- ///<param name="strIP">要查询的IP地址</param>
- ///<returns></returns>
- public IPLocation GetIPLocation(string strIP)
- {
- ip = IPToLong(strIP);
- ipFile = new FileStream(ipfilePath, FileMode.Open, FileAccess.Read);
- long[] ipArray = BlockToArray(ReadIPBlock());
- long offset = SearchIP(ipArray, 0, ipArray.Length - 1) * 7 + 4;
- ipFile.Position += offset;//跳过起始IP
- ipFile.Position = ReadLongX(3) + 4;//跳过结束IP
- IPLocation loc = new IPLocation();
- int flag = ipFile.ReadByte();//读取标志
- if (flag == 1)//表示国家和地区被转向
- {
- ipFile.Position = ReadLongX(3);
- flag = ipFile.ReadByte();//再读标志
- }
- long countryOffset = ipFile.Position;
- loc.country = ReadString(flag);
- if (flag == 2)
- {
- ipFile.Position = countryOffset + 3;
- }
- flag = ipFile.ReadByte();
- loc.area = ReadString(flag);
- ipFile.Close();
- ipFile = null;
- return loc;
- }
- ///<summary>
- /// 将字符串形式的IP转换位long
- ///</summary>
- ///<param name="strIP"></param>
- ///<returns></returns>
- public long IPToLong(string strIP)
- {
- byte[] ip_bytes = new byte[8];
- string[] strArr = strIP.Split(new char[] { '.' });
- for (int i = 0; i < 4; i++)
- {
- ip_bytes[i] = byte.Parse(strArr[3 - i]);
- }
- return BitConverter.ToInt64(ip_bytes, 0);
- }
- ///<summary>
- /// 将索引区字节块中的起始IP转换成Long数组
- ///</summary>
- ///<param name="ipBlock"></param>
- long[] BlockToArray(byte[] ipBlock)
- {
- long[] ipArray = new long[ipBlock.Length / 7];
- int ipIndex = 0;
- byte[] temp = new byte[8];
- for (int i = 0; i < ipBlock.Length; i += 7)
- {
- Array.Copy(ipBlock, i, temp, 0, 4);
- ipArray[ipIndex] = BitConverter.ToInt64(temp, 0);
- ipIndex++;
- }
- return ipArray;
- }
- ///<summary>
- /// 从IP数组中搜索指定IP并返回其索引
- ///</summary>
- ///<param name="ipArray">IP数组</param>
- ///<param name="start">指定搜索的起始位置</param>
- ///<param name="end">指定搜索的结束位置</param>
- ///<returns></returns>
- int SearchIP(long[] ipArray, int start, int end)
- {
- int middle = (start + end) / 2;
- if (middle == start)
- return middle;
- else if (ip < ipArray[middle])
- return SearchIP(ipArray, start, middle);
- else
- return SearchIP(ipArray, middle, end);
- }
- ///<summary>
- /// 读取IP文件中索引区块
- ///</summary>
- ///<returns></returns>
- byte[] ReadIPBlock()
- {
- long startPosition = ReadLongX(4);
- long endPosition = ReadLongX(4);
- long count = (endPosition - startPosition) / 7 + 1;//总记录数
- ipFile.Position = startPosition;
- byte[] ipBlock = new byte[count * 7];
- ipFile.Read(ipBlock, 0, ipBlock.Length);
- ipFile.Position = startPosition;
- return ipBlock;
- }
- ///<summary>
- /// 从IP文件中读取指定字节并转换位long
- ///</summary>
- ///<param name="bytesCount">需要转换的字节数，主意不要超过8字节</param>
- ///<returns></returns>
- long ReadLongX(int bytesCount)
- {
- byte[] _bytes = new byte[8];
- ipFile.Read(_bytes, 0, bytesCount);
- return BitConverter.ToInt64(_bytes, 0);
- }
- ///<summary>
- /// 从IP文件中读取字符串
- ///</summary>
- ///<param name="flag">转向标志</param>
- ///<returns></returns>
- string ReadString(int flag)
- {
- if (flag == 1 || flag == 2)//转向标志
- ipFile.Position = ReadLongX(3);
- else
- ipFile.Position -= 1;
- List<byte> list = new List<byte>();
- byte b = (byte)ipFile.ReadByte();
- while (b > 0)
- {
- list.Add(b);
- b = (byte)ipFile.ReadByte();
- }
- return Encoding.Default.GetString(list.ToArray());
- }
- }
- }
