Run a dialog in the background (SW_HIDE/SW_SHOW)

[abbz375]

Hey everyone,

I have multiple timers set up for a dialog (MFC) using SetTimer and OnTimer. This works great when I'm on the dialog but if I move away from the dialog and go back to it, the timers get reset, using the following code:

ShowWindow(SW_HIDE); 
test testDialog;  
testDialog.DoModal();

CTimersDlg main;
main.DoModal();  
OnOK(); // Close test dialog

The timer probably gets reset because of 'main.DoModal()' instead of main.ShowWindow(SW_SHOW).

Hiding the dialog works ok, but, if I use 'main.ShowWindow(SW_SHOW)' then I get a 'Debug Assertion Failed!' error. More info:

+		m_hWnd	0x00000000 {unused=??? }	HWND__ *

stops at this line:

ASSERT(::IsWindow(m_hWnd) || (m_pCtrlSite != NULL));

I think I'm getting this error because m_hWnd is 0x00000000 when it runs the code 'CTimersDlg main', so it creates a new dialog instead of looking at the one that was hidden? So how would I get the dialog that was hidden to re-appear? and will the timer still be running, without restarting?

My aim is to have the timer run in the background of that dialog even when I'm on another dialog so I thought I could hide the dialog and then show it when I want to get back to it, is this possible? Many thanks.