请斑竹和各路英豪帮我解决有关一个VxD例程 中的bug

我在调试下面这个 VxD实例时出现以下错误
.\dmach.cpp(38) : error C2248: 'hook' : cannot access public member declared in class 'VDMAChannel'

.\dmach.cpp(47) : error C2248: 'physicalMask' : cannot access public member declared in class 'VDMAChannel'

.\dmach.cpp(48) : error C2248: 'unhook' : cannot access public member declared in class 'VDMAChannel'

我不知时何原因,那位高手能帮俺解决这个讨厌的Bug,俺要好好谢谢这位高人！！。我把源程序附在下面

//DIOC.H

#define DMASAMPL_DIOC_TRANSFER_DATA 101

typedef struct {
 PVOID Address;
 DWORD Count;
} DMARegion;

// DMACH.h - include file for VxD DMACH

#include <vtoolscp.h>

#define DEVICE_CLASS DmachDevice
#define DMACH_DeviceID UNDEFINED_DEVICE_ID
#define DMACH_Init_Order UNDEFINED_INIT_ORDER
#define DMACH_Major 1
#define DMACH_Minor 0

class DmachDevice : public VDevice
{
public:
virtual BOOL OnSysDynamicDeviceInit();
virtual BOOL OnSysDynamicDeviceExit();
virtual DWORD OnW32DeviceIoControl(PIOCTLPARAMS pDIOCParams);

};

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

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

class DmachDMAChannel:VDMAChannel
{
public:
DmachDMAChannel();
void handler(VMHANDLE hVM);
};

// DMACH.cpp - main module for VxD DMACH

#define DEVICE_MAIN
#include "dmach.h"
Declare_Virtual_Device(DMACH)
#undef DEVICE_MAIN

#include "dioc.h"
static DmachDMAChannel *pDmasamplDMA=NULL;

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

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

BOOL DmachDevice::OnSysDynamicDeviceInit()
{

return TRUE;
}

BOOL DmachDevice::OnSysDynamicDeviceExit()
{

return TRUE;
}

DWORD DmachDevice::OnW32DeviceIoControl(PIOCTLPARAMS pDIOCParams)
{
DMARegion *pDMARegion1;
    DWORD Lockable;
    DWORD ErrCode;
    PVOID PhysAddr;
    switch(pDIOCParams->dioc_IOCtlCode)
{
     case DIOC_OPEN:
          pDmasamplDMA=new DmachDMAChannel;
          if(!pDmasamplDMA->hook())
 {
             delete pDmasamplDMA;
             return -1;
 }
          break;
    case DIOC_CLOSEHANDLE:
         if(pDmasamplDMA)
{
pDmasamplDMA->physicalMask(TRUE);
pDmasamplDMA->unhook();
delete pDmasamplDMA;
}
break;
    case DMASAMPL_DIOC_TRANSFER_DATA:
         if(!pDmasamplDMA) return -1;
pDMARegion1=(DMARegion *)pDIOCParams->dioc_InBuf;
if(pDmasamplDMA->lockRegion(pDMARegion1->Address,pDMARegion1->Count,0,Lockable,ErrCode,PhysAddr))
{
pDmasamplDMA->setRegion(NULL,TRUE,pDMARegion1->Address,pDMARegion1->Count,PhysAddr);
pDmasamplDMA->physicalUnmask(pDIOCParams->dioc_hvm,TRUE);
}
         else
{
VDMABuffer DmasamplBuffer(pDMARegion1->Address,pDMARegion1->Count);
if(!DmasamplBuffer.m_createError)
{
pDmasamplDMA->setRegion(&DmasamplBuffer,FALSE,pDMARegion1->Address,pDMARegion1->Count,DmasamplBuffer.m_physAddress);
                 pDmasamplDMA->physicalUnmask(pDIOCParams->dioc_hvm,TRUE);
DmasamplBuffer.copyFrom(pDMARegion1->Address,pDMARegion1->Count,0,ErrCode);
}
else return -1;
}
break;
     default: break;
}  
 return 0;

}

DmachDMAChannel::DmachDMAChannel():VDMAChannel(7)
{

}


void DmachDMAChannel::handler(VMHANDLE hVM)
{
static WORD count=0;
PVOID paddr;
DWORD num;
WORD mode;
count++;
dout<<"VM handle:"<<(DWORD)hVM<<endl;
dout<<"DMA Channel 3 used counts:"<<count<<endl;
getVirtualState(hVM,paddr,num,mode);
dout<<"Region Addr:"<<(DWORD)paddr<<endl;
dout<<"transfer Bytes:"<<num<<endl;
dout<<"transfer Mode:"<<mode<<endl;
}

# DMACH.mak - makefile for VxD DMACH

DEVICENAME = DMACH
DYNAMIC = 1
FRAMEWORK = CPP
DEBUG = 1
OBJECTS = dmach.OBJ

!include $(VTOOLSD)\include\vtoolsd.mak
!include $(VTOOLSD)\include\vxdtarg.mak

dmach.OBJ: dmach.cpp dmach.h



---
革命还未成功，我还需努力！

MSDN上的解释：
Compiler Error C2248
'member' : cannot access 'access' 'member' declared in class 'class'

The specified private or protected member of a class, structure, or union was accessed.

Tips

This error can be caused by attempting to access a member that is declared as private or protected, or by accessing a public member of a base class that is inherited with private or protected access. The member should be accessed through a member function with public access or should be declared with public access. The following is an example of this error:

class X
{
public:
   int  m_pubMemb;
   void setPrivMemb( int i ) { m_privMemb = i; }
protected:
   int  m_protMemb;
private:
   int  m_privMemb;
} x;

class Y : X {} y;    // default access to X is private

void main()
{
   x.m_pubMemb;      // OK, m_pubMemb is public
   x.setPrivMemb( 0 ); // OK, uses public access function
   x.m_protMemb;     // error, m_protMemb is protected
   x.m_privMemb;     // error, m_privMemb is private
   y.m_pubMemb;      // error, Y inherits X as private
   y.setPrivMemb( 0 ); // error, Y inherits X as private
}
--------------------------

我们可以看到
class Y : X {} y;    // default access to X is private
Y继承X时，默认是private

所以你的代码中
class DmachDMAChannel:VDMAChannel 改成
class DmachDMAChannel: public VDMAChannel 应该就可以了