背景：WM平台Camera程序开发：Windows Mobile SDK 6.0 Professional 包中的CameraCapture例子程序，这个例子程序是SDK的，我将它修改成MFC对话框工程。但是该程序没有预览功能，所以我要在它的基础上加上预览，主要修改了CGraphManager类的CreateCaptureGraphInternal函数和RunCaptureGraphInternal函数，然后自己加个自定义函数PreviewCaptureGraph用来预览。PreviewCaptureGraph函数是在主对话框类中调用间接调用的，不是像例子程序中那样什么都放到工作线程中（因为我发现放到线程中，函数会卡在pMediaControl->Run()处，所有我就自定义了PreviewCaptureGraph函数，改写了原来的RunCaptureGraphInternal()函数）

问题：现在可以预览，但是预览的效果如下所示：

PreviewCaptureGraph()函数中的CHK(pVideoWindow->SetWindowPosition(rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top));这句调用没有作用，函数调用本身并没有失败,而且发现前面两个参数有效，即left和top有效，可以改变预览的left和top坐标位置。希望那个预览的窗口可以填充满那个CStatic控件区域（黑色边框那个）。

对DirectShow不了解，希望有做过或者开发过的兄弟指点一下~

HRESULT CGraphManager::CreateCaptureGraphInternal()

{

	HRESULT       hr = S_OK;

	CComVariant   varCamName;

	CPropertyBag  PropBag;

	OAEVENT       oaEvent;

	WCHAR	      wzDeviceName[MAX_PATH + 1] = {0};



	CComPtr<IMediaEvent>            pMediaEvent;

	CComPtr<IGraphBuilder>          pFilterGraph;

	CComPtr<IBaseFilter>            pVideoEncoder;

	CComPtr<IBaseFilter>            pASFMultiplexer;

	CComPtr<IFileSinkFilter>        pFileSinkFilter;

	CComPtr<IPersistPropertyBag>    pPropertyBag;

	CComPtr<IDMOWrapperFilter>      pWrapperFilter;

	CComPtr<IBaseFilter>			pImageSinkFilter;



	//

	// Create the capture graph builder and register the filtergraph manager. 

	//

	CHK(m_pCaptureGraphBuilder.CoCreateInstance(CLSID_CaptureGraphBuilder));

	CHK(pFilterGraph.CoCreateInstance(CLSID_FilterGraph));

	CHK(m_pCaptureGraphBuilder->SetFiltergraph(pFilterGraph));





	//

	// Create and initialize the video capture filter

	//

	CHK(m_pVideoCaptureFilter.CoCreateInstance(CLSID_VideoCapture));

	CHK(m_pVideoCaptureFilter.QueryInterface(&pPropertyBag));



	// We are loading the driver CAM1 in the video capture filter. 

	CHK(GetFirstCameraDriver(wzDeviceName, MAX_PATH));

	varCamName = wzDeviceName;

	if(varCamName.vt != VT_BSTR)

	{

		ERR(E_OUTOFMEMORY);

	}



	CHK(PropBag.Write(L"VCapName", &varCamName));   

	CHK(pPropertyBag->Load(&PropBag, NULL));



	// Everything succeeded, the video capture filter is added to the filtergraph

	CHK(pFilterGraph->AddFilter(m_pVideoCaptureFilter, L"Video Capture Filter Source" ));





	// 

	// Third step: Create the video encoder DMO, load the WMV9 encoder, and 

	// add it to the graph

	//



	// Create the video encoder

	CHK(pVideoEncoder.CoCreateInstance(CLSID_DMOWrapperFilter ));

	CHK(pVideoEncoder.QueryInterface(&pWrapperFilter));



	// Load the WMV9 DMO

	CHK(pWrapperFilter->Init(CLSID_CWMV9EncMediaObject, DMOCATEGORY_VIDEO_ENCODER));



	// Everything succeeded, let's add the encoder to the graph

	CHK(pFilterGraph->AddFilter(pVideoEncoder, L"WMV9 DMO Encoder"));



	//

	// Create the ASF multiplexer and add it to the graph

	//

	CHK(m_pCaptureGraphBuilder->SetOutputFileName(&MEDIASUBTYPE_Asf, L"\\video1.asf", &pASFMultiplexer, &pFileSinkFilter));



	// Create preview 

	CHK(m_pCaptureGraphBuilder->RenderStream(&PIN_CATEGORY_PREVIEW, &MEDIATYPE_Video, m_pVideoCaptureFilter, NULL, NULL));

	//

	// Connect the video capture filter, the encoder and the multiplexer together

	// 

	CHK(m_pCaptureGraphBuilder->RenderStream(&PIN_CATEGORY_CAPTURE, &MEDIATYPE_Video, m_pVideoCaptureFilter, pVideoEncoder, pASFMultiplexer));



	//

	// Create the still image filter, and connect it to the video capture filter

	//

	CHK(pImageSinkFilter.CoCreateInstance(CLSID_IMGSinkFilter));

	CHK(pFilterGraph->AddFilter(pImageSinkFilter, L"Still image filter"));

	CHK(m_pCaptureGraphBuilder->RenderStream(&PIN_CATEGORY_STILL, &MEDIATYPE_Video, m_pVideoCaptureFilter, NULL, pImageSinkFilter));

	CHK(pImageSinkFilter.QueryInterface(&m_pImageSinkFilter));



	//

	// Prevent the data from flowing into the capture stream

	//

	CHK(m_pCaptureGraphBuilder->ControlStream(&PIN_CATEGORY_CAPTURE, &MEDIATYPE_Video, m_pVideoCaptureFilter, 0, 0 ,0,0));



	//

	// Let's get the handle for DShow events. The main loop will listen to both notifications from 

	// the UI thread and for DShow notifications

	//

	CHK(pFilterGraph->QueryInterface(IID_IMediaEvent, (void**) &pMediaEvent));

	CHK(pMediaEvent->GetEventHandle(&oaEvent));

	m_handle[1] = (HANDLE) oaEvent;



	m_bGraphBuilt = TRUE;



_CLEANUP:

	if(FAILED(hr))

	{

		NotifyMessage(MESSAGE_ERROR, _T("Building the graph failed"));

	}

	return hr;

}



HRESULT CGraphManager::RunCaptureGraphInternal()

{

	HRESULT hr = S_OK;



//	CComPtr<IGraphBuilder> pGraphBuilder;

// 	CComPtr<IMediaControl> pMediaControl;



	// Let's make sure that the graph has been initialized

	if((NULL == m_pCaptureGraphBuilder) || (FALSE == m_bGraphBuilt))

	{

		ERR(E_FAIL);

	}



	// Retrieve the filtergraph off the capture graph builder

//	CHK(m_pCaptureGraphBuilder->GetFiltergraph(&pGraphBuilder));





	// Get the media control interface, and run the graph

//	CHK(pGraphBuilder->QueryInterface(&pMediaControl));

//	CHK(pMediaControl->Run());



	CHK(NotifyMessage(MESSAGE_INFO, L"The Graph is Running ..."));



_CLEANUP:

	if(FAILED(hr))

	{

		NotifyMessage(MESSAGE_ERROR, L"Running The Capture Graph Failed");

	}



	PostMessage(m_hWnd, MSG_EVENTNOTIFICATION, 0, 0); // 这里我发送一个自定义消息到主对话框，在主对话框类的消息响应函数中调用PreviewCaptureGraph()函数。

	return hr;

}



HRESULT CGraphManager::PreviewCaptureGraph()

{

	HRESULT hr = S_OK;



	CComPtr<IGraphBuilder> pGraphBuilder;

	CComPtr<IMediaControl> pMediaControl;

	CComPtr<IVideoWindow>  pVideoWindow;



	// Let's make sure that the graph has been initialized

	if((NULL == m_pCaptureGraphBuilder) || (FALSE == m_bGraphBuilt))

	{

		ERR(E_FAIL);

	}



	// Retrieve the filtergraph off the capture graph builder

	CHK(m_pCaptureGraphBuilder->GetFiltergraph(&pGraphBuilder));



	// Previewer

	{

		ASSERT(m_hWndPreviewer);

		RECT rect = {0};

		GetClientRect(m_hWndPreviewer, &rect);

		CHK(pGraphBuilder->QueryInterface(&pVideoWindow));

		CHK(pVideoWindow->put_Owner((OAHWND)m_hWndPreviewer));

		CHK(pVideoWindow->put_WindowStyle(WS_CHILD | WS_CLIPSIBLINGS | WS_CLIPCHILDREN));

		CHK(pVideoWindow->SetWindowPosition(rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top));

		// 这里无效，SetWindowPosition()中的最后两个参数宽度和高度似乎没起作用

		CHK(pVideoWindow->put_Visible(OATRUE));



		//CHK(pMediaControl->Run());

	}



	// Get the media control interface, and run the graph

	CHK(pGraphBuilder->QueryInterface(&pMediaControl));

	//CHK(pMediaControl->Stop());

	CHK(pMediaControl->Run());



	CHK(NotifyMessage(MESSAGE_INFO, L"The Graph is Running ..."));



_CLEANUP:

	if(FAILED(hr))

	{

		NotifyMessage(MESSAGE_ERROR, L"Running The Capture Graph Failed");

	}

	return hr;

}