DirectShow 设置回调函数返回失败

[weixin_40211781]

如下设置回调函数 hr = m_pF->QueryInterface(IID_IVRControl, (void **)(&m_pVRControl)); 返回m_pVRControl为空；

是否IID_IVRControl错误? 有人遇到过吗？

// 接口的 GUID
static const GUID IID_IVRControl = {0x244df760, 0x7e93, 0x4cf0, {0x92, 0xf4, 0xdc, 0xb7, 0x9f, 0x64, 0x6b, 0x7e}};

IID_IVRControl

BOOL CDXGraph::CreateGrabber()
{
if(mGraph == NULL)
return FALSE;

HRESULT hr;

hr = CoCreateInstance(CLSID_lwVideoRenderer, NULL, CLSCTX_INPROC_SERVER,
IID_IBaseFilter, (void **)(&m_pF));

if(NULL == m_pF)
{

return false;
}

hr = mGraph->AddFilter(m_pF, L"VideoRenderer");

hr = m_pF->QueryInterface(IID_IVRControl, (void **)(&m_pVRControl));

return TRUE;
}

[zgl7903]

参考下 http://www.360doc.com/content/13/1105/10/10724725_326751558.shtml