IDirectSoundBuffer->QueryInterface 问题

[SayFun]

为什么获取QueryInterface会失败？有几种可能导致呢。
特别关注语音的录取播放，请有兴趣的Q近来聊聊

[shinesi]

看看你怎么写的，我的就没问题

HRESULT hRes;
IDirectSoundNotify * lpNotify;
DSBPOSITIONNOTIFY PosNotify;
PosNotify.dwOffset = DSBPN_OFFSETSTOP;
PosNotify.hEventNotify = m_hStopEvent1;

if( DS_OK != (hRes = m_lpDirectSound->CreateSoundBuffer(&dsbdesc, &m_lpPrimaryBuffer, 0)) ) {
m_lpPrimaryBuffer = 0;
return FALSE;
}
hRes = m_lpPrimaryBuffer->QueryInterface( IID_IDirectSoundNotify,
(VOID **)&lpNotify );
if ( hRes == S_OK )
{
hRes = lpNotify->SetNotificationPositions( 1,&PosNotify );
lpNotify->Release();
}