class NDC : public IO_OBJECT
{
    union {
        FILE_NOTIFY_INFORMATION fni;
        UCHAR buf[0x1000];
    };

    void Start()
    {
        HANDLE hFile;
        if (LockHandle(hFile))
        {
            if (IO_IRP* irp = new IO_IRP(this, 0, 0))
            {
                irp->CheckError(ReadDirectoryChangesW(hFile, buf, sizeof(buf), TRUE, FILE_NOTIFY_VALID_MASK, 0, irp, 0));
            }
            UnlockHandle();
        }
    }

    virtual void IOCompletionRoutine(CDataPacket* /*packet*/, DWORD /*Code*/, NTSTATUS status, ULONG_PTR dwNumberOfBytesTransfered, PVOID /*Pointer*/)
    {
        DbgPrint("IOCompletionRoutine(%u, %p)\n", status, dwNumberOfBytesTransfered);

        switch (status)
        {
        case NOERROR:
            union {
                PBYTE pb;
                PFILE_NOTIFY_INFORMATION pfni;
            };

            pfni = &fni;
            ULONG NextEntryOffset = 0;
            do
            {
                pb += NextEntryOffset;
                DbgPrint("[%u] %.*S\n", pfni->Action, pfni->FileNameLength / sizeof(WCHAR), pfni->FileName);
            } while (NextEntryOffset = pfni->NextEntryOffset);

            //Sleep(4000);// !!!

        case ERROR_NOTIFY_ENUM_DIR:
            Start();
        }
    }

public:
    ULONG Create(PCWSTR psz)
    {
        HANDLE hFile = CreateFileW(psz, FILE_GENERIC_READ, FILE_SHARE_VALID_FLAGS, 0, OPEN_EXISTING,
            FILE_FLAG_OVERLAPPED | FILE_FLAG_BACKUP_SEMANTICS, 0);//

        if (hFile != INVALID_HANDLE_VALUE)
        {
            Assign(hFile);

            if (ULONG dwError = IO_IRP::BindIoCompletion(hFile))
            {
                return dwError;
            }

            Start();

            return NOERROR;
        }

        return GetLastError();
    }
};

void DemoSpy(PCWSTR szFile)
{
    if (NDC* p = new NDC)
    {
        p->Create(szFile);
        MessageBoxW(0, 0, L"Start motitor and UI running", MB_ICONINFORMATION);
        p->Close();
        p->Release();
        MessageBoxW(0, 0, L"Stop monitor", MB_ICONINFORMATION);
    }
}