查询IP区段所在城市的函数

编程语言：C#
类    别：(网络应用，实用算法)
主要功能：查询一个IP所有的IP段.
关键:从Byte数组到ulong的转换出来的数字和 IPAddress.Address 返回值的是不一样的.

 

using System;

using System.Collections.Generic;

using System.Text;

using System.Net;

namespace IPUtility

{

    class Program

    {

        static void Main(string[] args)

        {

            IPRangeManage irm = new IPRangeManage();

            irm.Add(new IPRange("石家庄", "219.148.24.0", "219.148.63.255"));

            irm.Add(new IPRange("石家庄", "222.222.0.0", "222.222.63.255"));

            irm.Add(new IPRange("唐山", "219.148.64.0", "219.148.79.255"));

            irm.Add(new IPRange("保定", "219.148.20.0", "219.148.23.255"));

            Console.WriteLine(irm.Search("219.148.56.3").Name);

            Console.ReadLine();

        }

    }

    public class IPRange 

    {

        private string _Name = string.Empty;

        private ulong _BeginIP = 0;

        private ulong _EndIP = Int32.MaxValue;

        /**//// <summary>

        /// IP段名称

        /// </summary>

        public string Name

        {

            get { return _Name; }

            set { _Name = value; }

        }

        /**//// <summary>

        /// 开始IP

        /// </summary>

        public ulong BeginIP

        {

            get { return _BeginIP; }

            set { _BeginIP = value; }

        }

        /**//// <summary>

        /// 结束IP

        /// </summary>

        public ulong EndIP

        {

            get { return _EndIP; }

            set { _EndIP = value; }

        }

        /**//// <summary>

        /// 此IP段的范围

        /// </summary>

        public ulong Range

        {

            get

            {

                return EndIP - BeginIP;

            }

        }

        public IPRange(string name, string ipBegin, string ipEnd)

        {

            this.Name = name;

            this.BeginIP = IP2A(ipBegin);

            this.EndIP = IP2A(ipEnd);

        }

        public static ulong IP2A(string ip)

        {

            byte[] bytes = IPAddress.Parse(ip).GetAddressBytes();

            ulong ret = 0;

            foreach (byte b in bytes)

            {

                ret <<= 8;

                ret |= b;

            }

            return ret;

        }

        public static int Compare(IPRange x, IPRange y)

        {

            if(x.Range == y.Range)

                return 0;

            else if(x.Range > y.Range)

                return 1;

            else return -1;

        }

    }

    public class IPRangeManage

    {

        public IPRangeManage()

        { }

        private List< IPRange> _IPRangeList = new List< IPRange>();

        private bool _NeedSort = true;

        public void Add(IPRange ipRange)

        {

            _IPRangeList.Add(ipRange);

            _NeedSort = true;

        }

        private void Sort()

        {

            if (_NeedSort)

            {

                _IPRangeList.Sort(new Comparison<IPRange>(IPRange.Compare));

            }

        }

        public IPRange Search(string ipString)

        {

            ulong ip = IPRange.IP2A(ipString);

            this.Sort();

            foreach (IPRange ir in _IPRangeList)

            {

                if (ir.BeginIP <= ip && ir.EndIP >= ip)

                {

                    return ir;

                }

            }

            return null;

        }

    }

}