to lock an application - C / C++ / MFC Discussion Boards

Halloko15-Jan-04 5:49

15-Jan-04 5:49

Alexander M. wrote:
better use a loop with Sleep calls at the end.

..in an MFC app? How's that?

Alex Farber wrote:
You can use Multimedia Timer (see timeSetEvent) which has high precision

Do I really need higher precision? I mean, I just need to constantly update the view.
Anyways, you're suggesting that I shouldn't use the OnDraw() message to do the drawing but rather my own function?

Any other suggestions?

Re: OpenGL in an SDI app..!

LunaticFringe15-Jan-04 6:11

LunaticFringe

15-Jan-04 6:11

Use idle time processing. This is the technique you're looking for. If this is an MFC app, override OnIdle in the application class, and adapt the following handler code:

BOOL CAnApp::OnIdle(LONG lCount) <br />
{<br />
	  CWinApp::OnIdle(lCount);<br />
<br />
	  if (lCount >= 2)<br />
		    DoSomething();<br />
<br />
	  return(TRUE);<br />
}

Only do your processing when the lCount parameter is >= 2; the framework is doing it's thing when it's 0 and 1. If you return TRUE, the application will continue to call your OnIdle as long as the message queue is empty, and will re-commence calls to OnIdle after processing any messages that are received. Return FALSE and OnIdle will be called once (and only once) each time the message queue is emptied.

Re: OpenGL in an SDI app..!

Halloko15-Jan-04 7:35

Halloko

15-Jan-04 7:35

First off, thanks for the great answer!

LunaticFringe wrote:
if (lCount >= 2)
DoSomething();

Would you recommend invalidating the view in order to update my OGL window or should I use a separate function? I mean, after all, I DO need the device context of the view which is automatically passed as a parameter to OnDraw().

Re: OpenGL in an SDI app..!

LunaticFringe15-Jan-04 8:16

LunaticFringe

15-Jan-04 8:16

Yes. Invalidate, and perhaps call UpdateWindow to force the issue.

function with multiple arguments

hdaly15-Jan-04 2:11

hdaly

15-Jan-04 2:11

Hi,
Is it possible to write a function which will take a variable number of arguments????
What i'm passing in is an array of doubles, and at the moment my function looks like

void func(int num, double* arr)

with "num" been the number of elements in the array.
So, can I pass just the array, and work out the number of elements inside the function??

any ideas??
thanks,
henry

Re: function with multiple arguments

Michael P Butler15-Jan-04 2:26

Michael P Butler

15-Jan-04 2:26

Lookup va_start, va_arg and va_end in MSDN

int average( int first, ... )
{
int count = 0, sum = 0, i = first;
va_list marker;

va_start( marker, first ); /* Initialize variable arguments. */
while( i != -1 )
{
sum += i;
count++;
i = va_arg( marker, int);
}
va_end( marker ); /* Reset variable arguments. */
return( sum ? (sum / count) : 0 );
}

Michael

But you know when the truth is told,
That you can get what you want or you can just get old,
Your're going to kick off before you even get halfway through.
When will you realise... Vienna waits for you? - "The Stranger," Billy Joel

Re: function with multiple arguments

Michael Dunn15-Jan-04 5:09

Michael Dunn

15-Jan-04 5:09

hdaly wrote:
So, can I pass just the array, and work out the number of elements inside the function??

Not when using a plain array. Because you can't pass a whole array to a function, just a pointer to the first element, the way you have it now is the correct way. The alternative is to use an STL vector or other container that knows its size.

--Mike--
Ericahist | CP SearchBar v2.0.2 | Homepage | 1ClickPicGrabber New v2.0! | RightClick-Encrypt
Actual sign at the laundromat I go to: "No tinting or dying."

to lock an application

Idefix15-Jan-04 1:41

Idefix

15-Jan-04 1:41

Hi,

I need an idea to lock a MFC-Application after a specific time when no
user action happens.

The problem is:
The application has some internal messages like WM_TIMER, and some listctls get messages to display new text.

When the time is up the application has to lock itself and it appears a
login dialog.

Re: to lock an application [modified]

Marek Grzenkowicz15-Jan-04 4:17

Marek Grzenkowicz

15-Jan-04 4:17

Idefix wrote:
The problem is:
The application has some internal messages like WM_TIMER

Is this a problem?

You can have many timers. Each of them has an identifier.

I think that this should work:

void CMainFrame::OnStartTimer() 
{
   m_nTimer1 = SetTimer(1, 2000, 0);
   m_nTimer2 = SetTimer(2, 2000, 0);
}
 
void CMainFrame::OnTimer(UINT nIDEvent) 
{
   switch(nIDEvent)
   {
       case 1:
         // ...
         break;
       case 2:
         // ...
         break;
   }
 
   // Call base class handler.
   CMDIFrameWnd::OnTimer(nIDEvent);
}

Let me know if it helped.

modified on Monday, November 29, 2010 6:12 AM

Re: to lock an application

Idefix15-Jan-04 5:01

Idefix

15-Jan-04 5:01

Yes of course, the app can have many timer but how can I recognise
when the user has made no actions for e.g. 5 min. ?

At first I thought to use the OnIdle function but the internal WM_TIMER message
annul the idle state.

Another Problem is that the app is a client programm and get a lot of IP packets form the server and displays the data in controls. This are not user actions!

Re: to lock an application

Diddy15-Jan-04 5:37

Diddy

15-Jan-04 5:37

You can use GetLastInputInfo on Win2k to give you the time of the last "input" event - and compare that to the current time and then lock the app if the time out has gone

If you wanna run on 9x I think your into hook land - look up WH_FOREGROUNDIDLE - you might find this http://www.microsoft.com/msj/0200/c/c0200.aspx and this http://msdn.microsoft.com/msdnmag/issues/0500/c/default.aspx useful which do what you want.

Re: to lock an application

Rage15-Jan-04 7:42

Rage

15-Jan-04 7:42

I'd simply poll keyboard and mouse inputs in the message queue.

~RaGE();

Re: to lock an application

David Crow15-Jan-04 7:49

David Crow

15-Jan-04 7:49

One way would be to get the screen saver timeout value at the start of your application. Then set this value to whatever idle time you are interested in. Once that idle time has been reached, Windows will broadcast a SC_SCREENSAVE message. When your application ends, restore the screen saver timeout value to what it was.

Another idea that comes to mind would be to call SetWindowsHookEx(). As far as which type of hook to use, I don't know. Several of them look like they might work, but ultimately it'd probably be only one of them.

Classier ways may exist, but having never done this, I'm not familiar with them.

A rich person is not the one who has the most, but the one that needs the least.

Re: to lock an application

Idefix22-Jan-04 0:37

Idefix

22-Jan-04 0:37

Many thanks for your suggestions.

I realized the application lock to filter out
the messages WM_KEYDOWN, WM_SETCURSOR, WM_MOUSEMOVE ...

I use the WindowProc from CMainframe and PreTranslateMessage from the
Application to keep the user event in mind.
I set a timer to pull the last user event and divided the time of timer by 10.
When the timer the peeks the noted user event it puts them back. After 10 times without user events the applcations will be locked.

It goes well and is not so complicate.

I get another problem with messageboxes. When a messagebox appears there are no window messages Frown | :(

In addition I have to handle a opened messagebox.

At the moment I'm thinking about this problem.

Thanks

Re: to lock an application

Idefix22-Jan-04 1:47

Idefix

22-Jan-04 1:47

I'm so stupid.
Why I haven't tried GetLastInputInfo at first? (don't answer me)

That works very simple and it is what I wanted.

Thanks

Capture LButtonUp in a CListBox ??

jwd15-Jan-04 0:38

jwd

15-Jan-04 0:38

Hi,

I have at CListBox in a dialog box but I'm not able to capture mouse click (ex. LButtonUp() ) ?

Context-menu works fine on the mouse right click.

Can anybody help me ?

Re: Capture LButtonUp in a CListBox ??

Vladimir Georgiev15-Jan-04 0:51

Vladimir Georgiev

15-Jan-04 0:51

If the List box does not provide a way handle a message - WM_LBUTTONUP message in your case, you will have to use subclassing (write your own message procedure) for this control.

See the articles on subclassing here at CP, or at msdn.microsoft.com...

"Needless redundancy is the hobgoblin of software engineering." - Peter Darnell

Re: Capture LButtonUp in a CListBox ??

Diddy15-Jan-04 5:54

Diddy

15-Jan-04 5:54

Have MFC subclass it for you with a DDX_Control statment, if its based on a resource:

1. Derive a class from CListBox
2. Double click on the list box in the resource editor with CTRL held down
3. Select control
4. Select your new derived list box class
5. Give it a name

Then use class wizard to add a handler to your LB for WM_LBUTTONUP to your new LB

the problem of mscomm32.ocx and vc++

anders_zhou15-Jan-04 0:26

anders_zhou

15-Jan-04 0:26

hi!
I have complete my app using mscomm32.ocx,then it runs ok on my machine (os:win2k) which installed vc studio 6.0.But it can't run on the other machine (os:win2k) without intalling vc studio 6.0.
especially I register this ocx in the other machine.
why?
thanks!

load bitmap to dialog

Member 64882815-Jan-04 0:17

Member 648828

15-Jan-04 0:17

How can load bitmap into the dialog base......

IHTMLWindow4

Monty²15-Jan-04 0:07

Monty²

15-Jan-04 0:07

Can any one tell me where can i get the latest SDK if i want to use this interface

IHTMLWindow4

Live as if your were to die tomorrow. Learn as if you were to live forever.
-Mahatma Gandhi

Re: IHTMLWindow4

Prakash Nadar15-Jan-04 1:16

Prakash Nadar

15-Jan-04 1:16

I guess this must be in the platform sdk in webdevelopment section.

I Touched Osama Bin Ladens Bushy Beard

Resolving NetBIOS name for IP address

---Ranger---14-Jan-04 23:53

---Ranger---

14-Jan-04 23:53

Hi. Is everybody know how resolve NetBIOS name for some IP ?
PS Don't tell me about gethostbyaddr() . Need resolve NetBIOS rather than DNS.

Thanks

---Ranger---

Re: Resolving NetBIOS name for IP address

Alexander ^M.,15-Jan-04 5:27

Alexander ^M.,

15-Jan-04 5:27

i tried gethostbyname and it first querries a DNS server, if failed it scans for netbios!

don't use slogans like this again please!
---Ranger--- wrote:
PS Don't tell me about gethostbyaddr() . Need resolve NetBIOS rather than DNS.

Don't try it, just do it! Wink | ;-)

Re: Resolving NetBIOS name for IP address

---Ranger---15-Jan-04 17:45

---Ranger---

15-Jan-04 17:45

1. gehostbyaddr() too slowly for LAN (resolving timeout is too big)
2. Name rsolved by gethostaddr can be both DNS or NetBIOS.
I need ONLY NetBIOS names

---Ranger---

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