C / C++ / MFC

dllModule = LoadLibrary(_T("My.dll"));
if (dllModule) 
{
	CBTProcPtr = (HOOKPROC) GetProcAddress(dllModule, "CBTProc");
	if (CBTProcPtr)
		g_hHook = ::SetWindowsHookEx(WH_CBT, CBTProcPtr, dllModule, 0); 
}

#include "stdafx.h"
#include <TCHAR.H>
#include "strsafe.h"
BOOL APIENTRY DllMain( HMODULE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
					 )
{
    return TRUE;
}

LRESULT CALLBACK CBTProc(int nCode, WPARAM wParam, LPARAM lParam)
{
	TCHAR tempStr[1028] = {0};
	_stprintf_s(tempStr, _T("Inside CBTProc. nCode: %d\n"), nCode);
	OutputDebugString(tempStr);
	if (nCode == HCBT_CREATEWND)
	{
		OutputDebugString(L"Inside HCBT_CREATEWND\n");

		CBT_CREATEWND* wndData = (CBT_CREATEWND*)lParam;
		if (wndData && wndData->lpcs)
		{
			OutputDebugString(wndData->lpcs->lpszName);
			OutputDebugString(wndData->lpcs->lpszClass);
		}
	}

	return ::CallNextHookEx(0, nCode, wParam, lParam);
}

<br />
BOOL CReadComDlg::ConfigureCOMPort()<br />
{<br />
  CString strPort;<br />
  BOOL fSuccess;<br />
  iCOMPortNumber = 4;  //looked at the device manager to get this<br />
<br />
  strPort.Format("COM%d", iCOMPortNumber) ;<br />
<br />
  //Create the handle for reading from the COM port<br />
  //--returns a valid handle--<br />
  m_hFile =  CreateFile( strPort,                    <br />
			 GENERIC_READ | GENERIC_WRITE,<br />
		         (DWORD)NULL,	// exclusive access<br />
 			 NULL,			// no security<br />
		         OPEN_EXISTING,<br />
			 FILE_ATTRIBUTE_NORMAL,<br />
			 NULL	);		// hTemplate<br />
<br />
  //Check weather the handle is valid or not<br />
  if (INVALID_HANDLE_VALUE == m_hFile)<br />
  {<br />
    AfxMessageBox( "ERROR 2: unable to connect to COM port." );<br />
    return FALSE;<br />
  }<br />
<br />
<br />
  // suggest the buffer sizes for the COM port.<br />
  //--this function fails, error code 995 but according to MSDN, this is <br />
  //only a suggestion to the hardware so i suppose it is okay that it fails.--<br />
  SetupComm( m_hFile,		//handle<br />
	    (DWORD)2048,	//input buffer, in bytes<br />
	    (DWORD)2048);	//output buffer, in bytes<br />
<br />
	<br />
  //get the current control settings of the COM port<br />
  //--This function fails---<br />
  DCB dcb;<br />
  fSuccess = GetCommState(m_hFile,&dcb);<br />
<br />
  if (!fSuccess) <br />
  {<br />
    //--dError == 995<br />
    DWORD dError = GetLastError();<br />
<br />
    // Handle the error.<br />
    AfxMessageBox ("Error 3: Failed to Get the System Communication Settings.", MB_OK|MB_ICONEXCLAMATION );<br />
    return FALSE;<br />
  }<br />
.<br />
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}<br />