C / C++ / MFC

########### code use in admin application #############

DWORD dwApp = BSM_ALLDESKTOPS|BSM_APPLICATIONS;

BroadcastSystemMessage(BSF_POSTMESSAGE,&dwApp,UWM_SEND,0,(LPARAM)sSend.GetAt(i));

########################################################

void CDeviceList::GetDeviceList(std::vector<string> &info)
{
	int i = 0;
	HRESULT hr;

    // enumerate all video capture devices
	CComPtr<ICreateDevEnum> pCreateDevEnum;
    hr = CoCreateInstance(CLSID_SystemDeviceEnum, NULL, CLSCTX_INPROC_SERVER, IID_ICreateDevEnum, (void**)&pCreateDevEnum);
    if (hr != NOERROR)
	{
		return;
	}

    CComPtr<IEnumMoniker> pEm;
    hr = pCreateDevEnum->CreateClassEnumerator( CLSID_VideoInputDeviceCategory, &pEm, 0);
    if (hr != NOERROR) 
	{
		return;
    }


    pEm->Reset();
    ULONG cFetched;
    IMoniker *pM;
	char* name = new char[255];
	char* loc = NULL;

    while(hr = pEm->Next(1, &pM, &cFetched), hr==S_OK)
    {
		IPropertyBag *pBag;
		hr = pM->BindToStorage(0,0,IID_IPropertyBag,(void**)&pBag);
		if(SUCCEEDED(hr)) 
		{
			VARIANT var;
			var.vt = VT_BSTR;
			hr = pBag->Read(L"FriendlyName", &var, NULL);
			wcstombs(name, var.bstrVal, 255);
			
			if (hr == NOERROR) 
			{
				loc = strstr(name,"(VFW)");
				if (loc==NULL)
				{
					info.push_back(name);
				}
			}
			SAFE_RELEASE(pBag);
		}
		SAFE_RELEASE(pM);
    }
	delete[] name;
}

#include "StdAfx.h"
#include "DeviceHandler.h"

CDeviceHandler::CDeviceHandler(void)
{
//get device list in a string vector devList
dList.GetDeviceList(devList);  
}

void CDeviceHandler::start(void)
{
startThread = TRUE;
CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)ThreadProc, this, 0, NULL);
}

void CDeviceHandler::stop(void)
{
startThread = FALSE;
}

int CDeviceHandler::ThreadProc(LPVOID lpParam)
{
	CDeviceHandler* ptr = (CDeviceHandler*) lpParam;

	while(ptr->startThread)
	{
		vector<string> nList;
		ptr->dList.GetDeviceList(nList);

		char * cDeviceName = new char[260];
	int status = ptr->CompareLists(ptr->devList,nList,cDeviceName);
		switch(status)
		{
		case 0:	{
			TRACE("No Device Arrived nor Removed\n");
			}
			break;
		case 1:	{
			TRACE("Device Removed \"%s\"\n",cDeviceName);
			}
			break;
		case 2:	{
			TRACE("Device Arrived \"%s\"\n",cDeviceName);
			}
			break;
		}
		delete[] cDeviceName;
		ptr->devList = nList;
		Sleep(500);
	}
	return 0;
}

ptr->dList.GetDeviceList(nList);