看看怎么办？

遇到一个问题，请高手解答！
源代码：
//head file
#include <vtoolscp.h>

#define DEVICE_CLASS PortdevDevice
#define PORTDEV_DeviceID UNDEFINED_DEVICE_ID
#define PORTDEV_Init_Order UNDEFINED_INIT_ORDER
#define PORTDEV_Major 1
#define PORTDEV_Minor 0

#define PORT_NUM 0xf0
class PortdevDevice : public VDevice
{
public:
virtual BOOL OnSysDynamicDeviceInit();
virtual BOOL OnSysDynamicDeviceExit();
};

class PortdevVM : public VVirtualMachine
{
public:
PortdevVM(VMHANDLE hVM);
};

class PortdevThread : public VThread
{
public:
PortdevThread(THREADHANDLE hThread);
};

class mioportP:public VIOPort
{
public:
mioportP():VIOPort(PORT_NUM){};
DWORD handler(VMHANDLE hVM,DWORD port,CLIENT_STRUCT * pRegs, DWORD iotype,DWORD outdata);
};
//cpp file
#define DEVICE_MAIN
#include "portdev.h"
Declare_Virtual_Device(PORTDEV)
#undef DEVICE_MAIN

mioportP* pio;

PortdevVM::PortdevVM(VMHANDLE hVM) : VVirtualMachine(hVM) {}

PortdevThread::PortdevThread(THREADHANDLE hThread) : VThread(hThread) {}

BOOL PortdevDevice::OnSysDynamicDeviceInit()
{
pio=new(mioportP);
if (pio)
{
if (pio->hook())
{
dout<<"hook success"<<endl;
}
else
{
dout<<"hook unsuccess"<<endl;
return FALSE;
}
}
else
{
dout<<"Error new port"<<endl;
return FALSE;
}
return TRUE;
}

BOOL PortdevDevice::OnSysDynamicDeviceExit()
{
if (pio)
{
if(pio->unhook())
{
dout<<"unhook success"<<endl;
}
delete pio;
}
return TRUE;
}

DWORD handler(VMHANDLE hVM,DWORD port,CLIENT_STRUCT * pRegs, DWORD iotype,DWORD outdata)
{
static WORD count=0;
static WORD buffer[10];
static BYTE inppt=0;

count++;

dout<<"entering handler"<<endl;
dout<<"entered count:"<<count<<endl;
switch(iotype)
{
case BYTE_INPUT:
{
dout<<"buffer byte"<<(BYTE)buffer[inppt]<<endl;
inppt++;
return (BYTE) buffer[inppt-1];
}
case WORD_INPUT:
{
dout<<"buffer word"<<(WORD)buffer[inppt]<<endl;
inppt++;
return (WORD) buffer[inppt-1];
}
case DWORD_INPUT:
{
dout<<"buffer dword"<<(DWORD)buffer[inppt]<<endl;
inppt++;
return (DWORD) buffer[inppt-1];
}
case BYTE_OUTPUT:
{
buffer[count-1]=outdata;
dout<<"byte output data :"<<(BYTE)outdata<<endl;
break;
}
case WORD_OUTPUT:
{
buffer[count-1]=outdata;
dout<<"word output data :"<<(WORD)outdata<<endl;
break;
}
case DWORD_OUTPUT:
{
buffer[count-1]=outdata;
dout<<"dword output data :"<<(DWORD)outdata<<endl;
break;
}
default:break;
}
return 0;
}
//故障
portdev.OBJ : error LNK2001: unresolved external symbol "public: virtual unsigned long __thiscall mioportP::handler(struct cb_s *,unsigned long,union tagCLIENT_STRUC *,unsigned long,unsigned long)" (?handler@mioportP@@UAEKPAUcb_s@@KPATtagCLIENT_STRU
C@@KK@Z)
PORTDEV.VXD : fatal error LNK1120: 1 unresolved externals
NMAKE : fatal error U1077: 'E:\PROGRA~1\MICROS~1\VC98\bin\link.exe' : return code '0x460'
Stop.
Error executing NMAKE.
请帮忙，谢谢啦

帮帮我吧？！为什么都是连接错误？或者你们曾经遇到吗？

老兄，类应该用两个冒号（::）吧？
你的怎么都是一个呢？

我以前用vtoolsd时,用的链接器是bc5的linker.exe,不会出错,但换用bcb的ilinker.exe(增量链接器)便出错,错误类型似乎与你的错误相同,vc6的linker.exe也是增量链接器,我想可能换一个非增量链接器,或许可以纠正.

在函数handler(VMHANDLE hVM,DWORD port,CLIENT_STRUCT * pRegs, DWORD iotype,DWORD outdata) 前面少了mioportP：：，老雄