急！如何根据ip地址取得所在城市的信息？

Question

获得ip地址以后，如何取得该ip地址的信息呢？是通过ip库对照呢，还是有其他的办法，如果是ip库，请提供一个，谢谢！
环境，winform和asp。net页面

Answer 1

using System;
using System.IO;
using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions;
namespace ShowIP
{
    class IPReader
    {
         static private string _dataPath = "./QQWry.Dat"; 
         static private string country; 
         static private string local;   
         static private long firstStartIp=0; 
         static private long lastStartIp=0; 
         static private FileStream objfs = null; 
         static private long startIp=0; 
         static private long endIp=0; 
         static private int countryFlag=0; 
         static private long endIpOff=0; 
  
         #region 搜索匹配数据 
             static private int QQwry(string ip) 
             { 
                 string pattern = @"(((\d{1,2})|(1\d{2})|(2[0-4]\d)|(25[0-5]))\.){3}((\d{1,2})|(1\d{2})|(2[0-4]\d)|(25[0-5]))"; 
                 Regex objRe = new Regex(pattern); 
                 Match objMa = objRe.Match(ip); 
                 if(!objMa.Success) 
                 { 
                     return 4; 
                 } 
  
                 long ip_Int = IpToInt(ip); 
                 int nRet=0; 
                 if(ip_Int>=IpToInt("127.0.0.0")&&ip_Int<=IpToInt("127.255.255.255")) 
                 { 
                     country="本机内部环回地址"; 
                     local=""; 
                     nRet=1; 
                 } 
                 else if((ip_Int>=IpToInt("0.0.0.0")&&ip_Int<=IpToInt("2.255.255.255"))||(ip_Int>=IpToInt("64.0.0.0")&&ip_Int<=IpToInt("126.255.255.255"))||(ip_Int>=IpToInt("58.0.0.0")&&ip_Int<=IpToInt("60.255.255.255"))) 
                 { 
                     country="网络保留地址"; 
                     local=""; 
                     nRet=1; 
                 }                   
                 try 
                 {
                     objfs = new FileStream(_dataPath, FileMode.Open, FileAccess.Read);
                     //objfs.Seek(0,SeekOrigin.Begin); 
                     objfs.Position=0; 
                     byte[] buff = new Byte[8] ; 
                     objfs.Read(buff,0,8); 
                     firstStartIp=buff[0]+buff[1]*256+buff[2]*256*256+buff[3]*256*256*256; 
                     lastStartIp=buff[4]*1+buff[5]*256+buff[6]*256*256+buff[7]*256*256*256; 
                     long recordCount=Convert.ToInt64((lastStartIp-firstStartIp)/7.0); 
                     if(recordCount<=1) 
                     { 
                         country="FileDataError"; 
                         objfs.Close(); 
                         return 2; 
                     } 
                     long rangE=recordCount; 
                     long rangB=0; 
                     long recNO=0; 
                     while(rangB<rangE-1) 
                     { 
                         recNO=(rangE+rangB)/2; 
                         GetStartIp(recNO); 
                         if(ip_Int==startIp) 
                         { 
                             rangB = recNO; 
                             break; 
                         } 
                         if(ip_Int>startIp) 
                             rangB=recNO; 
                         else 
                             rangE=recNO; 
                     } 
                     GetStartIp(rangB); 
                     GetEndIp(); 
                     if(startIp<=ip_Int&&endIp>=ip_Int) 
                     { 
                         GetCountry(); 
                         local=local.Replace("（我们一定要解放台湾！！！）",""); 
                     } 
                     else 
                     { 
                         nRet=3; 
                         country="未知"; 
                         local=""; 
                     } 
                     objfs.Close(); 
                     return nRet; 
                 } 
                 catch 
                 { 
                     return 1; 
                 } 
  
             } 
         #endregion 
  
         #region IP地址转换成Int数据 
             static private long IpToInt(string ip) 
             { 
                 string[] ipArr = ip.Split('.');
                 if (ipArr.Length == 3)
                     ip = ip + ".0";
                 ipArr = ip.Split('.');
  
                 long  ip_Int=0;                 long p1 = long.Parse(ipArr[0]) * 256 * 256 * 256; 
                 long p2 = long.Parse(ipArr[1]) * 256 * 256;
                 long p3 = long.Parse(ipArr[2]) * 256;
                 long p4 = long.Parse(ipArr[3]);                 ip_Int=p1+p2+p3+p4; 
                 return ip_Int; 
             } 
         #endregion 
  
         #region int转换成IP 
             static private string  IntToIP(long ip_Int) 
             { 
                 long seg1=(ip_Int&0xff000000)>>24; 
                 if(seg1<0) 
                     seg1+=0x100; 
                 long seg2=(ip_Int&0x00ff0000)>>16; 
                 if(seg2<0) 
                     seg2+=0x100; 
                 long seg3=(ip_Int&0x0000ff00)>>8; 
                 if(seg3<0) 
                     seg3+=0x100; 
                 long seg4=(ip_Int&0x000000ff); 
                 if(seg4<0) 
                     seg4+=0x100; 
                 string ip=seg1.ToString()+"."+seg2.ToString()+"."+seg3.ToString()+"."+seg4.ToString();   
                 return ip; 
             } 
         #endregion 
  
         #region 获取起始IP范围 
             static private long GetStartIp(long recNO) 
             { 
                 long offSet = firstStartIp+recNO*7; 
                 //objfs.Seek(offSet,SeekOrigin.Begin); 
                 objfs.Position=offSet; 
                 byte [] buff = new Byte[7]; 
                 objfs.Read(buff,0,7); 
  
                 endIpOff=Convert.ToInt64(buff[4].ToString())+Convert.ToInt64(buff[5].ToString())*256+Convert.ToInt64(buff[6].ToString())*256*256; 
                 startIp=Convert.ToInt64(buff[0].ToString())+Convert.ToInt64(buff[1].ToString())*256+Convert.ToInt64(buff[2].ToString())*256*256+Convert.ToInt64(buff[3].ToString())*256*256*256; 
                 return startIp; 
             } 
         #endregion 
  
         #region 获取结束IP 
             static private long GetEndIp() 
             { 
                 //objfs.Seek(endIpOff,SeekOrigin.Begin); 
                 objfs.Position=endIpOff; 
                 byte [] buff = new Byte[5]; 
                 objfs.Read(buff,0,5); 
                 endIp=Convert.ToInt64(buff[0].ToString())+Convert.ToInt64(buff[1].ToString())*256+Convert.ToInt64(buff[2].ToString())*256*256+Convert.ToInt64(buff[3].ToString())*256*256*256; 
                 countryFlag=buff[4]; 
                 return endIp; 
             } 
         #endregion 
  

Answer 2

#region 获取国家/区域偏移量 
                  static private string GetCountry() 
                  { 
                      switch(countryFlag) 
                      { 
                          case 1:
                          case 2:
                              country = GetFlagStr(endIpOff + 4);
                              local=( 1 == countryFlag )?" ":GetFlagStr(endIpOff+8); 
                              break; 
                          default: 
                              country=GetFlagStr(endIpOff+4); 
                              local=GetFlagStr(objfs.Position); 
                              break; 
                      } 
                      return " "; 
                  } 
         #endregion 
  
         #region 获取国家/区域字符串 
                  static private string GetFlagStr(long offSet) 
                  { 
                      int flag=0; 
                      byte [] buff = new Byte[3]; 
                      while(1==1) 
                      { 
                          //objfs.Seek(offSet,SeekOrigin.Begin); 
                          objfs.Position=offSet; 
                          flag = objfs.ReadByte(); 
                          if(flag==1||flag==2) 
                          { 
                              objfs.Read(buff,0,3); 
                              if(flag==2) 
                              { 
                                  countryFlag=2; 
                                  endIpOff=offSet-4; 
                              } 
                              offSet=Convert.ToInt64(buff[0].ToString())+Convert.ToInt64(buff[1].ToString())*256+Convert.ToInt64(buff[2].ToString())*256*256; 
                          } 
                          else 
                          { 
                              break; 
                          } 
                      } 
                      if(offSet<12) 
                          return " "; 
                      objfs.Position=offSet; 
                      return GetStr(); 
                  } 
         #endregion 
 
         #region GetStr 
             static private string GetStr() 
             { 
                 byte lowC=0; 
                 byte upC=0; 
                 string str=""; 
                 byte[] buff =  new byte[2]; 
                 while(1==1) 
                 { 
                     lowC= (Byte)objfs.ReadByte(); 
                     if(lowC==0) 
                         break; 
                     if(lowC>127) 
                     { 
                         upC=(byte)objfs.ReadByte(); 
                         buff[0]=lowC; 
                         buff[1]=upC; 
                         System.Text.Encoding enc = System.Text.Encoding.GetEncoding("GB2312"); 
                         str+=enc.GetString(buff); 
                     } 
                     else 
                     { 
                         str+=(char)lowC; 
                     } 
                 } 
                 return str; 
             }     
         #endregion          /// <summary>
        /// 通过IP查找地理位置
        /// </summary>
        /// <param name="ip">ip地址</param>
        /// <returns>地理位置</returns>
        static public string FindIP(string ip)
        {
            QQwry(ip.Trim());
            return country +" "+ local;
        }
    }
}

Answer 3

纯真的IP库式可以导出成Txt文本形式的。下载的压缩包里面有一个查询IP的程序（ShowIP.exe），里面有一个“解压”的按钮，点这个就可以了。如果吧 “解压” 换成“导出”该多好呀，

Answer 4

到http://www.cz88.net/ 下载一个最新的IP库就可以了。自带了一个查询IP的程序（ShowIP.exe）。这个程序的作用是——把IP库转换成Txt格式。ShowIP.exe里的“解压”的按钮来实现。

Answer 5

用纯真库+Red_angelX(当你手淫你会想起谁)的代码