用MFC构造DirectX应用框架

用MFC构造DirectX应用框架(8)     {
        Msg("CreateSurface failed err=%d",ddrval);
        return FALSE;
    }
    else Msg("显示内存允许建立的缓冲区数=%d（最多需要3）",nBufferCount);
    DDSCAPS ddscaps;
    ddscaps.dwCaps=DDSCAPS_BACKBUFFER;
    ddrval=lpFrontBuffer->GetAttachedSurface(&ddscaps,&lpBackBuffer);
    if(ddrval!=DD_OK)
    {
        Msg("GetAttachedsurface failed err=%d",ddrval);
        return FALSE;
    }
    return TRUE;
}
void CDirectXWnd::Msg(LPSTR fmt,...)
{
    char buff[256];
    va_list va;
    lstrcpy(buff,"DirectxWnd:");
    va_start(va,fmt);
    wvsprintf(&buff[lstrlen(buff)],fmt,va);
    va_end(va);
    lstrcat(buff,"\r\n");
    AfxMessageBox(buff);
}
////////////////////////Virtual Function
BOOL CDirectXWnd::RestoreSurfaces()
{
    HRESULT ddrval;
    ddrval=lpFrontBuffer->Restore();
    if(ddrval!=DD_OK)
        return FALSE;
    return TRUE;
}
BOOL CDirectXWnd::CleanSurface()
{
    if(lpBackBuffer)
    {
        lpBackBuffer->Release();
        lpBackBuffer=NULL;
    }
    if(lpFrontBuffer)
    {
        lpFrontBuffer->Release();
        lpFrontBuffer=NULL;
    }