C / C++ / MFC

Re: How to make a window modal?

16-Jul-07 21:39

I have been trying to make a window (not dialog) modal without using any of the SDK/MFC functionality provided for this (I am trying to understand how it works internally), but it doesn't seem to be work. This is what I have tried.
* Create the main window with a button.
* On the button press, create a child window with its own windows proc (this will be our modal window) with a button on it (to close it)
* Disable the main window, show the child window and start a standard message loop.
* If the button on the child window is pressed set a flag to ensure we end the message loop
Unfortunately, as soon as the secondary (child window) loop starts, the whole UI freezes up - it responds to neither keyboard nor mouse events (although it still paints fine). Both my main as well as modal message loops are the same:

while (GetMessage (&msg, NULL, 0, 0))
{
   TranslateMessage (&msg) ;
   DispatchMessage (&msg) ;
}

The code above does not show the 'EndDialog' mechanism, but thats not the problem. I wish to know why keyboard and mouse events are not being handled. Therea are no issues if I dont start the message loop (ie. create a 'modeless' window).

--- NAF

Mark Salsbery17-Jul-07 6:08

Mark Salsbery

17-Jul-07 6:08

I imagine when you disable the main window, your child window gets disabled as well.

Maybe try disabling the main window before creating the child (that's what MFC does when
creating modal dialogs).

Mark

Mark Salsbery
Microsoft MVP - Visual C++

"Great job team! Head back to base for debriefing and cocktails."

Re: How to make a window modal?

DevMentor.org17-Jul-07 7:02

DevMentor.org

17-Jul-07 7:02

you might need to set the focus to the child window, otherwise it will not get keyboard and mouses messages, are you doing this?

Yours Truly, The One and Only!

Re: How to make a window modal?

Navaid Alam18-Jul-07 0:55

18-Jul-07 0:55

I have tried that, but doesn't work Frown | :(

Anyway, the focus is required only for the keyboard not the mouse.

Using timers

minkowski16-Jul-07 21:27

16-Jul-07 21:27

Hi,

I am a bit confused on how to make and use a timer. Currently I have

<br />
void MyClass::func()<br />
{<br />
<br />
<br />
            UINT m_Timer = SetTimer(1, 2000, 0);<br />
            CMainFrame *pFrame = (CMainFrame *)AfxGetMainWnd();<br />
	            ASSERT(pFrame != NULL);<br />
            pFrame->OnTimer(1);<br />
<br />
}<br />

where

<br />
void CMainFrame::OnTimer(UINT nIDEvent) <br />
{<br />
	<br />
	FlashScreen();<br />
	CWnd::OnTimer(nIDEvent);<br />
<br />
}<br />
<br />

I wish the screen to blink every 2 seconds. What I dont understand in the examples I have seen is that OnTimer is not explicitly called. So if you have 2 timers how does each timer know which OnTimer to call? I know that the 1st parameter in the SetTimer function is the nIDEvent which is supposed to be assciociated with the OnTimer() to uniquely identify the timer. I hope that you could provide me with an example where OnTimer is invoked? Thanks!

Navaid Alam16-Jul-07 21:46

16-Jul-07 21:46

OnTimer() is not supposed to be called directly, rather when the timer expires, your app will receive a message and this handler will get called. If you have more than one timer, the nIDEvent should be used to identify it. This is the same value that you passed to SetTimer() as the first argument. So you should specify different values for the first param for each timer attached to a particular window.

minkowski16-Jul-07 22:01

16-Jul-07 22:01

Hey thanks for your reply. So in my class where I have defined the function

<br />
void CMainFrame::OnTimer(UINT nIDEvent) <br />
{<br />
	<br />
	FlashScreen();<br />
	CWnd::OnTimer(nIDEvent);<br />
<br />
}<br />

you're saying it is invoked when the time expires as defined in the SetTimer() function (in my case 2000ms). I put a break point in the function above but unfortunately it was not hit... errr isn't it supposed to be if the function is invoked after the 2000ms?

Thanks.

Navaid Alam16-Jul-07 23:35

16-Jul-07 23:35

yes it should happen after 2s, if its not happening perhaps you have not set up the message map for WM_TIMER?

minkowski17-Jul-07 0:25

17-Jul-07 0:25

Yes, that was the problem. I needed

<br />
ON_WM_TIMER()<br />

Thanks for your help.

Cedric Moonen16-Jul-07 21:49

Cedric Moonen

16-Jul-07 21:49

I'm not sure if I understood correctly your question. Anyway, you don't have to call OnTimer yourself. This function will be called by the framework when a specific timer fires. The framework will pass in the nIDEvent parameter the Id of the timer that fired. So, for all the timers that expire, you will have only one OnTimer function. In the function, it is up to you to do some specific things depending of the timer (you could use a switch statement and do several different things depending on the Id you receive).

Hope that helps.

Cédric Moonen
Software developer

Charting control [v1.2]

minkowski16-Jul-07 22:03

16-Jul-07 22:03

Hey thanks for that. Yes, I was unsure whether I should have invoked the OnTimer() function or if windows does itself.

minkowski16-Jul-07 22:17

16-Jul-07 22:17

Hi,

So in my class where I have defined the function

<br />
void CMainFrame::OnTimer(UINT nIDEvent) <br />
{<br />
<br />
FlashScreen();<br />
CWnd::OnTimer(nIDEvent);<br />
<br />
}<br />

I put a break point in the function above but unfortunately it was not hit... errr isn't it supposed to be if the function is invoked after the 2seconds which was defined in my SetTimer()?

Thanks for any advice.

Where can i find Class Wizard in VS2005

Abhijeet Pathak16-Jul-07 22:18

Abhijeet Pathak

16-Jul-07 22:18

hi,
the OnTimer() function is not supposed to be called directly...

http://www.codeproject.com/system/timers_intro.asp this will be helpful to you...
Smile | :)

yaminisridaran16-Jul-07 21:24

yaminisridaran

16-Jul-07 21:24

I am new to VS2005. I want to add the paint member function to my class which is derived from CStatic. I am trying to find class wizard in VS2005 but not able to find it.
Help me

S.Yamini

prasad_som16-Jul-07 22:21

prasad_som

16-Jul-07 22:21

Here[^] it is.

Prasad
MS MVP - VC++

yaminisridaran16-Jul-07 23:11

yaminisridaran

16-Jul-07 23:11

Thanks. I am facing a runtime problem . I am getting the below error after the dialog is displayed.
TODO: <file description=""> has encountered a problem and needs to close.
and then the application closes

S.Yamini

prasad_som16-Jul-07 23:51

prasad_som

16-Jul-07 23:51

yaminisridaran wrote:
after the dialog is displayed

Which dialog your are talking about ?
Is it dialog for entering function name etc.
Or some thing from your application. If it is former, you probably need to fix the VS installation.

Prasad
MS MVP - VC++