PumpMessage Question - C / C++ / MFC Discussion Boards

Re: Change IDR_MAINFRAME start coordinate

sortegrip2-Feb-07 4:56

2-Feb-07 4:56

What would I center it against and where in my CView or CDoc would I do it?
I only have one window and in the center of that window I draw the GUI on the DC in OnDraw().

Re: Change IDR_MAINFRAME start coordinate

David Crow2-Feb-07 5:17

David Crow

2-Feb-07 5:17

sortegrip wrote:
What would I center it against...

That all depends on the argument you pass to it. By default, it centers child windows relative to their parent window, and pop-up windows relative to their owner.

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

Destroyed Window

baerten2-Feb-07 2:21

baerten

2-Feb-07 2:21

I have a TabControl ( not the MFC one ) on my View.
In this Tab i have a huge number of Views.
If the User clicks in the Menu on "Customers" it opens the customers in this current Tab, if he
clicks on articles, so it opens the articles AND DOESN'T erase the Customers-View, because he can re-open the used-View with the old-state ...

So i need to close/delete all these views if the Tab closes...
In the "destructor" of the Tab i close all opened Views from this Tab

But if i close the whole application, it doesn't close the Tab ( which closes the Views )
It closes the Views, then the Tabs, then the TabControl

If he steps into the Destructor of the Tab, the Pointers of the Views are still there,
but their hWnd aren't valid anymore...

Now the question : How can i test, if a pointer on a View has a valid hWnd or if the object behind
the pointer is still deleted ?

It's certainly possible or not?

Thanks Rose | [Rose]

Re: Destroyed Window

Mark Salsbery2-Feb-07 5:41

Mark Salsbery

2-Feb-07 5:41

if (::IsWindow(*pView))
// HWND is valid
else
// HWND is NOT valid

Re: Destroyed Window

baerten4-Feb-07 21:40

baerten

4-Feb-07 21:40

Thanks for your answer.

But this dont work Sniff | :^)

Because the pointer is already 0xcdcdcdcd. If the pointer is 0x000000 i could test him on
if(View!=NULL) or can i test also on 0xcdcdcdcd ?
Is it a special-adress-value for deleted objects? Because if an instance is deleted, the pointer
sets to 0xcdcdcdcd ...

Thanks Smile | :)

Re: Destroyed Window

Mark Salsbery5-Feb-07 5:19

Mark Salsbery

5-Feb-07 5:19

If your "views" or "tabs" are derived from CFrameWnd then they delete themselves when you call
DestroyWindow(). Therefore you should set the pointers to NULL so you can check them before
trying to use them.

It's up to you to track the lifetime of these objects. That means if any child windows of a
given window class are not CFrameWnd derived and are allocated with new then the child object
should be deleted - usually this is done in a WM_DESTROY handler of the parent.

To destroy a CFrameWnd derived window
pFrameWnd->DesstroyWindow();
pFrameWnd = NULL;

To destroy a CWnd derived window
pWnd->DesstroyWindow();
delete pWnd;
pWnd = NULL;

Re: Destroyed Window

Mark Salsbery5-Feb-07 5:25

Mark Salsbery

5-Feb-07 5:25

And no, don't test on 0xcdcdcdcd - that's a debug value but there's no guarantee the CRT will
change a pointer to that value when it's deleted. It's up to the programmer to keep track of
all that Smile | :)

PumpMessage Question

Andy2022-Feb-07 1:26

Andy202

2-Feb-07 1:26

I am using a Tabbed Dialog (6 dialogs in total).

Now in some of these Tabbed Dialogs I need to wait for an external event, so I do the following:-

while(waiting)
{
   Sleep(100);           // Wait 100 ms
   ProcessMessages();    // Pump Message Queue
   CheckForEvent();      // Call the routine that will set waiting to false when OK
}

void ProcessMessages()
{
   CWinApp* pApp = AfxGetApp();
   MSG msg;

   while(PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE))
      pApp->PumpMessage();
}

But my question is 'Do I need to have a separate ProcessMessage in each of the Tabbed Dialogs' and are they a better way of doing this sort of processing.
Note I use a 3rd party API for the external event.

Many thanks,

Andy.

Re: PumpMessage Question

David Crow2-Feb-07 2:41

David Crow

2-Feb-07 2:41

Andy202 wrote:
I need to wait for an external event...

So why aren't you using CreateEvent() and WaitForSingleObject()?

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

Re: PumpMessage Question

Andy2022-Feb-07 2:46

Andy202

2-Feb-07 2:46

Hi David, its just trying to gt something working (prototye) fast.

Are they problems with several ProcessMessages as the number of Tabbed Dialogs could go up to 20!

Cheers,

Andy.

Re: PumpMessage Question

David Crow2-Feb-07 2:56

David Crow

2-Feb-07 2:56

Andy202 wrote:
Are they problems with several ProcessMessages...

Other than PeekMessage() being old and antiquated? Yes. If you happen to have (in the future) an active modeless dialog, there is no call to IsDialogMessage(). Is PumpMessage() dispatching its own messages?

While it's ultimately up to you as to how you want to handle event notification, I personally would not opt for this route.

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

Re: PumpMessage Question

Waldermort2-Feb-07 2:48

Waldermort

2-Feb-07 2:48

If I understand your code correctly, when the external event occurs, a message is posted/sent to the dialog. Is this correct? If so, you don't need keep calling PeekMessage(). GetMessage() will wait until there is a message in the que and only return if there is.

Also you say 'tabbed dialog' Do you mean a window with a tab control, or a series of windows? If you have one main window, which controls your dialogs, then you only need one message pump. If you are dialing with several windows, then create a "message only window" which handles the message pump and dispatches the message to the correct child dialog. Either way, you only need one message pump.

Re: PumpMessage Question

Andy2032-Feb-07 9:25

Andy203

2-Feb-07 9:25

Thanks for your post.

I am using the CTabCtrl class from the Code Project, which has a dialog for each Tab.

For the case of Timers, I handle these time events in the controller Tab, should I just need to place the ProcessMessage() in this place also.

I did have 2 ProcessMessage() in different Tabs, but the progra, runs slow.

Andy (at home)

Basic MFC questions..

Sameer_Thakur2-Feb-07 1:12

Sameer_Thakur

2-Feb-07 1:12

Hi all,
Have some basic questions related to MFC….
1. Which are the DLLs that are used in a simple application that I created thr VC++6.0.? I know MFC42.DLL Smile | :)

which are the other important ones?
2. In which DLL the definition of WinMain(),DefWindowProc() is provided? I know that I can’t edit it but just to have basic information…
3. What is the effect of various setting under ProjectSettingsGeneral tabMicrosoft foundation classes 
i. Use MFC in a shared DLL,
ii. ii. Use MFC in Static library,
iii. iii. Not using MFC

Thanks

Sameer

Re: Basic MFC questions..

led mike2-Feb-07 5:05

led mike

2-Feb-07 5:05

1. Read the documentation
2. I don't know and don't care
3. Using MFC shared DLL's allows your application to use the MFC classes and minimizes the size of your EXE. Static linking of the MFC libraries results in linking the MFC libraries into your EXE build. Therefore the EXE is larger but not dependent on MFC being installed on the machine. Not using MFC means your application cannot use the MFC classes.

led mike

Re: Basic MFC questions..

prasad_som2-Feb-07 7:15

prasad_som

2-Feb-07 7:15

To add to mikes reply,

Sameer_Thakur wrote:
1. Which are the DLLs that are used in a simple application that I created thr VC++6.0.? I know MFC42.DLL which are the other important ones?

Use dependency walker to check dll's used

Prasad
Notifier using ATL | Operator new[],delete[][^]

Re: Basic MFC questions..

Hamid_RT3-Feb-07 5:32

Hamid_RT

3-Feb-07 5:32

What do you need exactly?

WhiteSky

deleting the multiple rows in Grid

reddy harish2-Feb-07 0:20

reddy harish

2-Feb-07 0:20

Hi Iam using Grid control in my application.
how to delete the multiple rows in the Grid.
currently if i select multiple rows to delete but the last selected row is getting deleted.here iam sending the code what i have used to delete the rows.but it is working

pls any body can help in this
CCellRange cRange;
int nCount = 0;
UINT unSel = 0;
INT_PTR nSelctedDMItemsCount = 0;
cRange = m_Grid.GetSelectedCellRange();
nCount = cRange.GetMaxRow();
bool bFlag = false;
for(int nDMIdx = 1;nDMIdx < nCount;nDMIdx++)
{
bFlag =false;
bFlag = m_Grid.IsCellSelected(nDMIdx,0);
if(bFlag )
{
m_Grid.DeleteRow( nDMIdx );

}
}

Re: deleting the multiple rows in Grid

led mike2-Feb-07 5:05

led mike

2-Feb-07 5:05

reddy harish wrote:
Hi Iam using Grid control

What Grid Control?

led mike

Re: deleting the multiple rows in Grid

reddy harish4-Feb-07 19:03

reddy harish

4-Feb-07 19:03

Iam using CGrid control.in this iam facing the problem

Re: deleting the multiple rows in Grid

Hamid_RT3-Feb-07 5:33

Hamid_RT

3-Feb-07 5:33

Yes what grid control?

WhiteSky

How to remove the AM/PM text in CDateTimeCtrl ?

Hemant kulkarni1-Feb-07 23:19

Hemant kulkarni

1-Feb-07 23:19

Hi,

I created a CDateTimeCtrl control on my view. It is a 24 hour time format. But it still displays AM/PM . If it is 24 hr clock them AM/PM is not necessary there. SO I want to remove the AM/Pm text from control. How can I do this?

Regards,
Hemant Kulkarni.

Re: How to remove the AM/PM text in CDateTimeCtrl ?

Naveen2-Feb-07 0:54

Naveen

2-Feb-07 0:54

use CDateTimeCtrl::SetFormat to change this behaviour

nave

Re: How to remove the AM/PM text in CDateTimeCtrl ?

Hemant kulkarni2-Feb-07 2:19

Hemant kulkarni

2-Feb-07 2:19

Thanks!

I got the solution

It is just to change the SetFormat() finction and not to pass tt t options in string

VC++ 2005 iostream input problem for unsigned int

Alex Aimer1-Feb-07 23:11

Alex Aimer

1-Feb-07 23:11

Hello,

porting my sipmle (hope, C++ standard conforming) console programs from VC++ 2003 to VC++2005 I found out that I can't read unsigned int from the stream if there is a comma after it.

...main...{
unsigned int ui=2345;
cin >> ui;
cout << ui; // still will show 2345 on input "1,1"
}

Input "1,1" prevents reading 1 to ui. The reason is that deep inside the num_get class of the VC2005 iostream library thinks that in the current locale comma is thousand separator. But there is no reason for it. (I don't even mention locales in my program, so it should be standard "C" locale.)

Any sensible suggestions? I want (and could before) reading

// This also affects boost::uBLAS library at matrix input.

Regards,
Alex

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