根据IP+掩码，求IP网段

例如：

源文件

allofchina 58.28.0.0/16 

转化后

allofchina 58.28.0.0/16 974913536 974979071

 

974913536 是该网段的最小，即58.28.0.0

974979071 是该网段的最大，即58.28.255.255

 

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;

namespace ConsoleApplication1
{
    class Program
    {

        static UInt32 IPv4StringToInt32(string strIP)
        {
            IPAddress ipAddress;
            if (IPAddress.TryParse(strIP,out ipAddress))
            {
                if (ipAddress.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork)
                {
                    byte[] bytes = ipAddress.GetAddressBytes();
                    return (UInt32)(bytes[0] << 24 | bytes[1] << 16 | bytes[2] << 8 | bytes[3]);
                }
            }
            return 0;
        }

        static void Main(string[] args)
        {
            string line;
            System.IO.StreamReader file = new System.IO.StreamReader("E:\\IP\\ipsect.txt"); //In_File

            System.IO.StreamWriter file2 = new System.IO.StreamWriter("E:\\IP\\out.txt"); //Out_File

            while ((line = file.ReadLine()) != null)
            {
                string OutString=line;
                //OutString.Replace('\n', '\0');

                //line: allofchina    58.28.0.0/16

                if(line.Length > 0) //排除空行

                {
                    string[] temp = line.Split('\t');
                    //temp[0]: allofchina temp[1]: 58.28.0.0/16

                    {
                        string[] tempp = temp[1].Split('/');
                        //tempp[0]: 58.28.0.0 tempp[1]: 16

                        string ip = tempp[0];
                        UInt32 mask = byte.Parse(tempp[1]);

                        UInt32 mask_for_min = 0;
                        UInt32 mask_for_max = 0;
                        UInt32 bit=1;
                        for (int i = 0; i < 32-mask;i++ )
                        {
                            mask_for_max |= bit;
                            bit <<= 1;
                        }
                        mask_for_min = ~mask_for_max;

                        UInt32 IP = IPv4StringToInt32(ip);

                        UInt32 min = IP & mask_for_min;
                        UInt32 max = IP | mask_for_max;

                        Console.Write(mask.ToString());
                        Console.Write("\t");
                        Console.Write(mask_for_min.ToString());
                        Console.Write("\t");
                        Console.WriteLine(mask_for_max.ToString());
                        
                        OutString+="\t"; OutString+=min.ToString();
                        OutString += "\t"; OutString += max.ToString();
                 
                    file2.WriteLine(OutString);
                    }
                }
            }
            file.Close();
            file2.Close();
            Console.ReadLine();
        }
    }
}