C / C++ / MFC

29-Jul-04 22:53

i have written an application which i start at boot time. now, when the system is shut down, i don't do anything explicitly in my application. i know, when the system goes down, it sends WM_QUERYENDSESSION message and when all the application returns a non-zero value, it sends a WM_ENDSESSION message. Now, how do i handle this message in my dailog based application. I need to handle this message coz i need to change a registry entry when the system shuts down. the classwizard does not show the handling of such message.

pliz help.

Michael P Butler29-Jul-04 23:11

29-Jul-04 23:11

You'll have to manually add the ON_WM_ENDSESSION() entry to the message map and add a void OnEndSession(BOOL bEnding) function to handle the message.

Michael

CP Blog [^]

Anonymous29-Jul-04 23:41

29-Jul-04 23:41

hi Michael,

i manually added the ON_WM_ENDSESSION() and in the OnEndSession(BOOL bEnding) function did the necessary regitry changes. Now, the application responds to shutdown. but it also responds when i log off. i do not want my application to make any registry changes when i just log off. how do i differentiate between 'SHUT DOWN' and 'LOG OFF'. should i handle WM_QUERYENDSESSION messge instead of WM_ENDSESSION.

Michael P Butler30-Jul-04 0:01

30-Jul-04 0:01

If you want to detect whether the session is ending due to a Log-off then you need to handle the WM_QUERYENDSESSION message. The lParam value of the message contains the info of the session end state.

Michael

CP Blog [^]

Antony M Kancidrowski30-Jul-04 0:23

30-Jul-04 0:23

The problem here is that you can not use the functions OnEndSession and OnQueryEndSession as they do not get the lParam passed through from the MFC message handler.

Ant.

I'm hard, yet soft.
I'm coloured, yet clear.
I'm fruity and sweet.
I'm jelly, what am I? Muse on it further, I shall return! - David Williams (Little Britain)

Antony M Kancidrowski30-Jul-04 0:04

30-Jul-04 0:04

This is not that straight forward. The flags that are sent are in the LPARAM of the message but are not directly accessable from the OnEndSession virtual function.

If you override the MFC message handler you can check the LPARAM for ENDSESSION_LOGOFF.

LRESULT CALLBACK CMainFrame::NewMsgHandlerFn(HWND hWnd,UINT uMsg,WPARAM wParam, LPARAM lParam)
{
  if( uMsg == WM_ENDSESSION )
  {
    // Check the lParam for ENDSESSION_LOGOFF
    if( lParam & ENDSESSION_LOGOFF )
    {
      // Do something to flag logoff
      return true;
    }

  }
  return CallWindowProc(s_pOldMsgHandler,hWnd,uMsg,wParam,lParam);
}

I hope that helps.

Ant.

I'm hard, yet soft.
I'm coloured, yet clear.
I'm fruity and sweet.
I'm jelly, what am I? Muse on it further, I shall return! - David Williams (Little Britain)

Michael P Butler30-Jul-04 0:35

30-Jul-04 0:35

Its been a while since I did any MFC but can't you just

ON_MESSAGE(WM_ENDSESSION, OnMyEndSession)

and

LRESULT OnMyEndSession(WPARAM wParam, LPARAM lParam)
{
return 1;
}

Michael

CP Blog [^]

Antony M Kancidrowski30-Jul-04 1:08

30-Jul-04 1:08

That is a very good point. I seem to have over complicated the situation.

Aw, well at least it is an exercise in subclassing. Unsure | :~

Ant.

I'm hard, yet soft.
I'm coloured, yet clear.
I'm fruity and sweet.
I'm jelly, what am I? Muse on it further, I shall return! - David Williams (Little Britain)

Michael P Butler30-Jul-04 1:11

30-Jul-04 1:11

Antony M Kancidrowski wrote:
That is a very good point. I seem to have over complicated the situation.

You know me, if there is an quick, easy way to do something I'll use it. Subclassing is just too much like hard-work. Thats why I use C# now, less work to do. Big Grin | :-D

Michael

CP Blog [^]

Anonymous30-Jul-04 1:21

30-Jul-04 1:21

WOW!
both the solution worked
but i decide to go with the easier solution... Smile | :)

i handle WM_ENDSESSION message on log-off and shut down seperately.
well, thnx all

Anonymous30-Jul-04 0:42

30-Jul-04 0:42

Tried to incorporate the function suggested by u.
there is a compile error in
CallWindowProc(s_pOldMsgHandler,hWnd,uMsg,wParam,lParam);

Error:::'s_pOldMsgHandler':undeclared identifier

will u please elaborate the callback function and also the idenfifier 's_pOldMsgHandler'

Antony M Kancidrowski30-Jul-04 0:53

passing parameters to a running program

30-Jul-04 0:53

Sorry,
s_pOldMsghandler is defined.

static PMSGHANDLERFN s_pOldMsgHandler;

then in the .cpp

PMSGHANDLERFN CMainFrame::s_pOldMsgHandler;

Subclass the message handler in a Subclass function

void CMainFrame::Subclass()
{
:
  s_pOldMsgHandler = (PMSGHANDLERFN)SetWindowLong(m_hWnd,GWL_WNDPROC,(LONG)NewMsgHandlerFn);
:
}

Ant.

I'm hard, yet soft.
I'm coloured, yet clear.
I'm fruity and sweet.
I'm jelly, what am I? Muse on it further, I shall return! - David Williams (Little Britain)

ting66829-Jul-04 22:35

ting668

29-Jul-04 22:35

HI~

Is there any function in eVC++ which can pass some parameters to a running C# program?

"CreateProcess" can pass some parameters as a argument when a process start. However, how about the process is running?

Thanks~

Re: passing parameters to a running program [modified]

Antony M Kancidrowski29-Jul-04 22:46

Re: passing parameters to a running program

29-Jul-04 22:46

If you look for IPC and/or Interprocess Communication this should help you out.

Sorry forgot to say: If you look in the eVC++ help that is!

Ant.

I'm hard, yet soft.
I'm coloured, yet clear.
I'm fruity and sweet.
I'm jelly, what am I? Muse on it further, I shall return! - David Williams (Little Britain)

GDavy29-Jul-04 22:46

GDavy

29-Jul-04 22:46

I don`t know if this is THE way to pass data, but in my case I`
use shared memory... And protect access by a global mutex
Check out the funcs
CreateFileMapping to create the shared mem portion and
MapViewOfFile to get access to the mem portion, and use a named
mutex to prevent read-write errors between apps.

`Hope this helps,
Davy

Beginner - OLE DB - bind to grid control

poptcat29-Jul-04 21:56

poptcat

29-Jul-04 21:56

Hi. I try to connect to a Microsoft SQL database using Ole Db - IRowSet interface. This works, but I can't bind it to a grid control (I use Microsoft Datagrid control).
I have:
IRowset* pRowset;
DDX_Control(pDX, IDC_DATAGRID1, m_grid);
........................................
I try to bind by
m_grid.SetRefDataSource((LPUNKNOWN)pRowset);
but it raises an exception : Type mismatch.
Well, I tried - I suppose . Could someone help me?
Gabi

failed to create empty document

Anonymous29-Jul-04 21:24

Re: failed to create empty document

29-Jul-04 21:24

hi all,
i have converted a Form view based application to cview now im facing an error when i run the application the error is "failed to create empty document". please do reply . thanks in advance
Haseeb Ahmed

Michael P Butler29-Jul-04 23:16

Logging data in MS-ACCESS......few problems!!!

29-Jul-04 23:16

It could be one of many things. The only way to succesfully solve these problems is to put a breakpoint at the beginning on the InitInstance method and step through the code until the error is thrown.

Michael

CP Blog [^]

Anonymous29-Jul-04 20:48

Re: Logging data in MS-ACCESS......few problems!!!

29-Jul-04 20:48

i have a log file which is a MS-access database. i have the following problem:-

1. wat is the name of the MS-access driver so that i can package it with my application and it can run on any machine irrespective of whether that machine has MS-access installed or not?

2. my log size increases very quickly. i want to rotate the log(i.e, something like syslog in Linux which rotates log weekely)

wat should i do?

David Crow30-Jul-04 2:51

David Crow

30-Jul-04 2:51

Anonymous wrote:
wat is the name of the MS-access driver...

Look at the Drivers tab on the ODBC Data Source Administrator dialog. It shows:

Microsoft Access Driver (*.mdb)

Anonymous wrote:
2. my log size increases very quickly. i want to rotate the log...

Add a date/time field to the table, and index it. Periodically run through the rows, deleting those that have "expired."

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

Re: Logging data in MS-ACCESS......few problems!!!

avenger_sb2530-Jul-04 8:28

avenger_sb25

30-Jul-04 8:28

I dont know much but... "Ms Access uses JET DATABASE DRIVER". You use ODBC which acts as an interface between your application and JET

...Avenger

Remember... testing & debugging are always part of programming ...so exterminate those stinking bugs

Not able to set properties of newly developed Activex Control at run time

samhita29-Jul-04 18:26

samhita

29-Jul-04 18:26

I have developed activex control in MFC. It is text control with additional features.
I am testing it in VB.
Design time properties are getting set.
When I try to set the properties at run time and execute the application I am getting the following error.
If I try to access text property
error is as follows
Method text of object '_DoleEdit' failed

function to determine the adminstrator and integration with a dialog based app

Anonymous29-Jul-04 18:13