用以前放在牛腩公用类库里的IPSearch就行了，编译没有错误，不过直接用发现中文乱码，一通乱改才发现问题，看最后的ReadString方法 ，
using
System;
using
System.
Collections.
Generic;
using
System.
Text;
using
System.
IO;
namespace
Niunan.
WebAssign.
Util
{
///
<summary>
/// 提供从纯真IP数据库搜索IP信息的方法；
/// 感谢LumaQQ提供纯真IP数据库格式文档；
/// ----HeDaode 2007-12-28 四川教育学院
///
</summary>
internal
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;
}
///
<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.
GetEncoding(
"GB2312").
GetString(
list.
ToArray());
//.net core下用这个，要不然会出中文乱码
//return Encoding.Default.GetString(list.ToArray()); //.netframework下用这个
}
}
}