请问dll文件

应该是这样的格式写么？
// myPhaDll.cpp : Defines the entry point for the DLL application.
//
#include "stdafx.h"
#include "myPhaDll.h"
#include "define.h"
#include "winioctl.h"
BOOL APIENTRY DllMain( HANDLE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
                                         )
{
    switch (ul_reason_for_call)
        {
                case DLL_PROCESS_ATTACH:
                case DLL_THREAD_ATTACH:
                case DLL_THREAD_DETACH:
                case DLL_PROCESS_DETACH:
                        break;
    }
    return TRUE;
}
// This is an example of an exported variable
MYPHADLL_API int nMyPhaDll=0;
// This is an example of an exported function.
MYPHADLL_API bool fnMyPhaDll(void)
{
        return true;
}
// This is the constructor of a class that has been exported.
// see myPhaDll.h for the class definition
CMyPhaDll::CMyPhaDll()
{
        return;
}
extern "C"
{
        MYPHADLL_API int myAdd(int a, int b)
        {
                return a*b;
        }
        MYPHADLL_API bool InitDevice()          // = createfile
        {
                hDev = CreateFile(LINKNAME,
                                  GENERIC_READ | GENERIC_WRITE,
                                  FILE_SHARE_READ | FILE_SHARE_WRITE,
                                  NULL,
                                  OPEN_EXISTING,
                                  FILE_ATTRIBUTE_NORMAL,
                                  NULL);
                if (hDev== INVALID_HANDLE_VALUE)
                        return FALSE;
                else
                        return TRUE;
        }
        MYPHADLL_API bool StartDevice()         // = START_HANDLE
        {
                if (!DeviceIoControl(hDev, DdDRIVER_IOCTL_START, NULL, 0, NULL, 0, &nOutput
, NULL))
                        return FALSE;
                else
                        return TRUE;
        }
        
        MYPHADLL_API bool StopDevice()          // = STOP_HANDLE
        {
                if(DeviceIoControl(hDev,DdDRIVER_IOCTL_STOP,NULL,0,NULL,0,&nOutput,NULL
))
                        return FALSE;
                else
                        return TRUE;
        }
        MYPHADLL_API int doRead(int i)
        {
                return outdata[i];
        }
}