C / C++ / MFC

bool Foo::open()
{
  // Lock shared resource - return if unable
  ASSERT (Foo::m_pFile == NULL);
  Foo::m_pFile = fopen ("\\foo\bar\derf.dat", "w");
  if (Foo::m_pFile == NULL)
     return (false);

  // Rest of method
  ...
  return (true);
}

Foo foo_1;
bool bStatus = foo_1.open();
ASSERT (bStatus);  // succeeds (file is created)

Foo foo_2;
bStatus = foo_2.open();
ASSERT (!bStatus);  // <--- fails (file is recreated)

void CSearchDlg::OnSearch() <br />
{<br />
	// TODO: Add your control notification handler code here<br />
	 CString strEngine;<br />
    int nReturnValue;<br />
<br />
    UpdateData();         //Transfer data from controls to variables<br />
    <br />
    m_strSearch = m_strSearchFor;<br />
    //get currently selected text<br />
    nReturnValue=GetDlgItemText(IDC_ENGINE, strEngine); <br />
    <br />
    UpdateData(FALSE);      //Transfer data from variables to controls<br />
    <br />
    if(nReturnValue>0)      //Check for Search engine selection<br />
    {<br />
        if(strEngine=="Yahoo")<br />
        {<br />
            m_strSearch = "http://search.yahoo.com/search?p=" <br />
                                + m_strSearch;<br />
            ShellExecute(NULL, "open", m_strSearch, <br />
                        NULL,NULL,SW_SHOWDEFAULT);<br />
        }<br />
<br />
        else if(strEngine=="Altavista")<br />
       {<br />
            m_strSearch = <br />
                "http://www.altavista.digital.com/cgi-bin/query?" + "<br />
               pg=q&what=web&fmt=.&q="<br />
			   + m_strSearch;<br />
            ShellExecute(NULL, "open", m_strSearch,<br />
               NULL,NULL,SW_SHOWDEFAULT);<br />
       }<br />
<br />
        else if(strEngine=="Excite")<br />
        {<br />
            m_strSearch = "http://www.excite.com/search.gw?trace=a&search="<br />
                                +m_strSearch;<br />
            ShellExecute(NULL, "open", m_strSearch,<br />
                NULL,NULL,SW_SHOWDEFAULT);<br />
        }<br />
<br />
        else if(strEngine=="Askjeeves")<br />
        {<br />
            m_strSearch = "http://www.askjeeves.com/AskJeeves.asp?ask="<br />
                                +m_strSearch;<br />
            ShellExecute(NULL, "open", m_strSearch,<br />
                NULL,NULL,SW_SHOWDEFAULT);<br />
        }<br />
<br />
<br />
    }<br />
}

#pragma data_seg .....

HWND    g_hWndServer    = NULL;  // window to my application

#pragma data_seg()
#pragma comment(linker, ....


//
//...
//

LRESULT CALLBACK KeyboardTracker( int code, WPARAM wParam, LPARAM lParam )
{
        if (code==HC_ACTION) 
        {
                
                if ( wParam == VK_F9 )
                {      
                        PostMessage(g_hWndServer, VK_F9, 0, 0);                 
                } 
                
                
        }
        return ::CallNextHookEx(g_hHkKeyboard, code, wParam, lParam);
}


// Function to start the hook
//
__declspec(dllexport) BOOL TrackerInit(HWND hWnd)
{
        if ( g_hHkKeyboard == NULL ) 
        {
                g_hHkKeyboard = SetWindowsHookEx( WH_KEYBOARD, KeyboardTracker, g_hInstance, 0 );
        }
        
        
        
        _ASSERT(g_hHkKeyboard);
        
        
        if ( !g_hHkKeyboard )
        {
                return FALSE;
        }
        else /* hook success */
        {
                g_hWndServer = hWnd;
                return TRUE; 
        }
}


//
//...
//

// My application which use the DLL

BOOL CMyApplicationDlg::OnInitDialog()
{
	CDialog::OnInitDialog();

	
	SetIcon(m_hIcon, TRUE);			
	SetIcon(m_hIcon, FALSE);

        
        HWND hWnd = NULL; <<<<<<<======== // how can I hand over the main dialog of my appliction here???????
        TrackerInit(hWnd); // call the DLL-function to start key hook


	return TRUE;  
}