C / C++ / MFC

22-Jul-04 23:12

Hi,

Is there a rule of MFC that does not allow thread creation from CMainFrame?

The situation is the following:

I have a menu function that wants to create a thread using

::CreateThread (NULL, 0, (LPTHREAD_START_ROUTINE) ThreadAnalyse, &m_stThreadArg, 0, &dw);

The ThreadAnalyse Function is a static global function, not a member of CMainFrame. The m_stThreadArg is a member of CMainFrame and contains 4 pointer to the CMainFrame Object and 3 pointers to other data.

However it appears that once the menu handler function has returned the whole computer hangs up and runs very slowly. If I place a break point in the Thread function the function is not called for a very long time. Once the function returns the computer returns to normal operational conditions and timings.

Does anyone know why this is?

regards,
RichardS

"Programming today is a race between software engineers striving to build bigger and
better idiot-proff programs, and the Universe trying to produce bigger and better idiots.
So far the Universe is winning." -- Rich Cook

valikac23-Jul-04 5:10

valikac

23-Jul-04 5:10

Where in CMainFrm() does the program call CreateThread()?

Kuphryn

RichardS23-Jul-04 5:34

23-Jul-04 5:34

The function is an afx message handler from a menu.

void CMainFrame::OnFileOpenstream (void) is the prototype.

"Programming today is a race between software engineers striving to build bigger and
better idiot-proff programs, and the Universe trying to produce bigger and better idiots.
So far the Universe is winning." -- Rich Cook

palbano23-Jul-04 7:55

palbano

23-Jul-04 7:55

RichardS wrote:
contains 4 pointer to the CMainFrame Object

Do not pass MFC objects across threads. This is a well known issue and is documented on MSDN.

"No matter where you go, there your are." - Buckaroo Banzai

-pete

RichardS23-Jul-04 22:00

23-Jul-04 22:00

I have found that if I put a :Sleep (10) after creating tehe thread it runs fine. Do you know where the MSDN documentation for this is?

"Programming today is a race between software engineers striving to build bigger and
better idiot-proff programs, and the Universe trying to produce bigger and better idiots.
So far the Universe is winning." -- Rich Cook

palbano25-Jul-04 19:04

palbano

25-Jul-04 19:04

RichardS wrote:
I have found that if I put a :Sleep (10) after creating tehe thread it runs fine. Do you know where the MSDN documentation for this is?

There should be no reason for that to change the behavior of your thread unless there is some problem in your code. No it is not documented that I know of since I don't believe it is any type of feature.

"No matter where you go, there your are." - Buckaroo Banzai

-pete

David Crow23-Jul-04 9:33

David Crow

23-Jul-04 9:33

Why are you not using AfxBeginThread()?

"When I was born I was so surprised that I didn't talk for a year and a half." - Gracie Allen

RichardS23-Jul-04 21:58

DDV/DDX with propertypages

23-Jul-04 21:58

I am used to writing non-MFC applications/libraries so CreateThread was the only alternative that I knew about.

"Programming today is a race between software engineers striving to build bigger and
better idiot-proff programs, and the Universe trying to produce bigger and better idiots.
So far the Universe is winning." -- Rich Cook

Robberto C.22-Jul-04 22:50

Robberto C.

22-Jul-04 22:50

Hi,

In my code i use a dialog which contains a propertysheet with multiple propertypages.

All propertypages contain comboboxes and editboxes for the user to fill in.

I would like to have all the propertypages validated [B]as soon as the Ok button
of the dialog is pressed[/B]. This means probably that i can not place validation code in DoDataExchange(), because this function is called everytime when a tab is switched.

The Address Book of Microsoft which can be found in 'Programs->Accessories' also uses this kind of validation. It validates the pages as soon as OK is pressed, not between switching tabs.

How can i do this?

Re: DDV/DDX with propertypages

PJ Arends23-Jul-04 7:10

PJ Arends

23-Jul-04 7:10

Do your validating in OnOK()

"You're obviously a superstar." - Christian Graus about me - 12 Feb '03

"Obviously ??? You're definitely a superstar!!!" mYkel - 21 Jun '04

Within you lies the power for good - Use it!

How, knowing handler of window, attach other window to him.

Anton Zarubin22-Jul-04 22:45

Anton Zarubin

22-Jul-04 22:45

How, by the WinApi facilities, knowing handler of window, attach other window to him, for example button.

//======================================
HWND hWnd1 = FindWindow(NULL, "TestWnd");
HWND hWnd2 = CreateWindow("button", "TestButton", WS_CHILD, 0,0,100,100, hWnd1, NULL, NULL, NULL);
ShowWindow(hWnd2, SW_SHOW);
UpdateWindow(hWnd2);
//======================================

Show me please, where I wrong.

Re: How, knowing handler of window, attach other window to him.

Timothy Grabrian23-Jul-04 13:55

Timothy Grabrian

23-Jul-04 13:55

As far as I know, you can not make windows in another process other than your own.

wWw.KruncherInc.cOm - My cool programs

CListCtrl InsertItem

Atif Mushtaq22-Jul-04 22:20

Atif Mushtaq

22-Jul-04 22:20

In Report style fot a list ctrl .

When I insert items , every new item enters at the top , so if I enter 1,2,3,4 in list control one by one it will look like

4
3
2
1
although i choose the Sorting to None.
But I want that every new item should be entered at bottom and i also dont want sorting , sequence in my case is very important.

So how to insert every new item at the last of list ctrl. to have such kind of result
1
2
3
4
where 1 entered first , 2 secondly and so on.

Unmanaged in a .NET world

Re: CListCtrl InsertItem

Arjan Schouten23-Jul-04 0:15

Arjan Schouten

23-Jul-04 0:15

int InsertItem( int nItem, LPCTSTR lpszItem );

nItem is the index in the ListCtrl where your item gets if you insert, it sound like you have hardcoded it to 0.

to enter 1, 2, 3, 4 do

InsertItem(0, "1");
InsertItem(1, "2");
InsertItem(2, "3");
InsertItem(3, "4");

Arjan

Re: CListCtrl InsertItem

V.23-Jul-04 1:13

23-Jul-04 1:13

if I'm not mistaken AddString or something should add items at the bottom off the list. InsertItem will insert the item at a given position.

"If I don't see you in this world, I'll see you in the next one... and don't be late." ~ Jimi Hendrix

Re: CListCtrl InsertItem

David Crow23-Jul-04 9:34

David Crow

23-Jul-04 9:34

V. wrote:
if I'm not mistaken AddString...

... is a CListBox() method.

"When I was born I was so surprised that I didn't talk for a year and a half." - Gracie Allen

SetSystemCursor in VC++

5iveboy22-Jul-04 21:56

5iveboy

22-Jul-04 21:56

hi,
I use SetSystemCursor to change the normal mouse cursor to something else, and 2 seconds later change it back to it's original. I can change the cursor the first time. but the second change does not happen until the first change is called once again. Please advise.
thanks a million Roll eyes | :rolleyes:

, see below.
ps. CopyCursor doesn't seem to work.

this is inside a function that is called every 4 seconds:

at the end of 1 second change mouse cursor from normal to appstarting

hCurCopy = LoadCursor(NULL, IDC_APPSTARTING);<br />
SetSystemCursor(hCurCopy,OCR_NORMAL);

later in the code
at the end of 3 seconds change cursor from appstaring to normal

hCurNorm = LoadCursor(NULL,IDC_ARROW);<br />
SetSystemCursor(hCurNorm,OCR_APPSTARTING)

Re: SetSystemCursor in VC++

erkanina22-Jul-04 22:17

erkanina

22-Jul-04 22:17

Use following codes

//... Set Your Cursor
SetCapture();
SetCursor(AfxGetApp()->LoadCursor(IDC_APPSTARTING));

//... Restore to old
ReleaseCapture();
SetCursor(AfxGetApp()->LoadCursor(IDC_ARROW));

My Program will not install on Windows NT 4

LittleYellowBird22-Jul-04 21:55

LittleYellowBird

22-Jul-04 21:55

I've just had an error reported by a customer saying that my VC++6 Program will not install on Windows NT 4. They say there is an 'error message concerning 6883 in the MFC42.DLL'.

Anyone seen this before? What can I do about it? We haven't got an NT machine to try it on so I am a bit stumped at the moment!

Any ideas?

Ali

Arjan Schouten23-Jul-04 0:04

Arjan Schouten

23-Jul-04 0:04

The DLL on your customers machine is out of date, it can't export the function with ordinal 6883. Try supplying your customer with a newer DLL or beter yet, link your program statically so it won't need the customers DLL!

Arjan

LittleYellowBird23-Jul-04 2:33

LittleYellowBird

23-Jul-04 2:33

Thanks, for the help - sounds like one quuick fix and one more permanent fix. I've never considered linking any differently - I will look into it.

By the way, what are the pro's & con's of linking statically & dynamically?
Any problems I should look out for?

Thanks Again Smile | :)

Ali

Navin23-Jul-04 2:58

Navin

23-Jul-04 2:58

General rule of thumb - always link statically!

You have found the "con" of linking dynamically - if the libraries (MFC42.DLL and MSVCRT.DLL) are out of date on your customer system, then you'll have to redistribute them - and that is a royal pain.

The "con" of linking statically is that your executable will be a little bigger. It is also a little trickier if you call another MFC DLL and try to share memory/data between the two.

An expert is somebody who learns more and more about less and less, until he knows absolutely everything about nothing.