C / C++ / MFC

4-Jan-05 1:24

Hey there...

I'm having a problem with MessageBox(HWND, char*, char*, UINT). I'm writing C++ to the WinAPI, no high level abstractions other than those that I roll (ie no MFC, ATL, or managed extentions).

I have a main window created with WNDCLASSEX. Durig WM_CREATE, a couple dialog boxes are created and displayed to help guide the user through a couple of setup steps. The problem lies in calling MessageBox(...) from any of these dialogs. Any attempt to display a MessageBox(...) results in a system beep, all GUIs lose focus, but the MessageBox never appears.

If I run the debugger, I can watch the system get to the MessageBox(...), execute it, return IDOK, then the debugger quits and lets the application resume, never executing any code that follows.

If I remove the calls to show and update the main window (in WinMain(...)), then the dialogs can display MessageBox(...) as normal. The Dialogs are also able to call one another with no ill effects, regardless of whether or not I show the main window.

Now, I have a template I have written over time, which includes WinMain, WinProc(...), etc, so I just have to cut and paste to get an application started, and none of my previous applications have ever had a problem like this. I have spent days now, comparing this app to previous ones, and I simply cannot find a difference between the architecture and the calls (nor the way I use them).

I have tried everything I can think of, tweaking every dialog attribute there is, changing the calls and the order the are invoked. One other note, if I invoke a MessageBox(...) from within WM_CREATE, all is fine, its only after the ShowWindow() and UpdateWindow() calls that this behaviour starts to exhibit itself.

Has anyone ever seen this behavior before? Have any idea what it is that I could have done wrong this time?

Some code samples follw this post.

Thank you for reading all this and any help you might be able to offer

Dave

p.s. compiling with VC++ 7.1 on Win XP Pro

from WinMain....

// store the instance
DAT->hInst = instance;

MSG msg;
WNDCLASSEX wcex;
HWND hWnd = NULL;

// build the windows struct
wcex.cbSize = sizeof( WNDCLASSEX );
wcex.style = CS_HREDRAW | CS_VREDRAW;
wcex.lpfnWndProc = (WNDPROC)WinProc;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = 0;
wcex.hInstance = DAT->hInst;
wcex.hIcon = LoadIcon( DAT->hInst, (LPCTSTR)ICO_GLOGO );
wcex.hCursor = LoadCursor( NULL, IDC_ARROW );
wcex.hbrBackground = (HBRUSH)GetStockObject( GRAY_BRUSH );
wcex.lpszMenuName = (LPCTSTR)MENU_MAIN;
wcex.lpszClassName = gas::sAPPNAME.c_str();
wcex.hIconSm = LoadIcon( wcex.hInstance, (LPCTSTR)ICO_GLOGO );

if( !RegisterClassEx(&wcex) )
{
MessageBox( NULL, "Error Registering Window: Need NT?", "Application Error", MB_ICONERROR | MB_OK );
}
else
{
hWnd = CreateWindow( gas::sAPPNAME.c_str(), std::string(gas::sAPPNAME + " " + gas::APPVER).c_str(), WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, DAT->hInst, NULL );
if( !hWnd )
MessageBox( NULL, "Error Creating Window: NULL Handle Returned!", "Application Error", MB_ICONERROR | MB_OK );
else
gas::Data::hMain = hWnd;
}

// everything is done, give the user the application window
ShowWindow( hWnd, showcmd );
UpdateWindow( hWnd );

// welcome the user if they still wish to be
if( CFG->GetShowWelcomePrompt() && gas::Data::hWelcome ) {
ShowWindow( gas::Data::hWelcome, SW_SHOW );
SetFocus( gas::Data::hWelcome );
}

while( GetMessage( &msg, NULL, 0, 0 ) > 0 )
{
if( !IsDialogMessage( DAT->hSplash, &msg ) &&
!IsDialogMessage( DAT->hDataSrc, &msg ) &&
!IsDialogMessage( DAT->hWelcome, &msg ) )
{
TranslateMessage( &msg );
DispatchMessage( &msg );
}
}

return( static_cast<int>( msg.wParam ) );

from WinProc::WM_CREATE

case WM_CREATE:
{
// gonna do a simplified splash screen for now
// later this is where we'll retreive startup data
// and perform synchronization
gas::CreateSplashDlg( hwnd );
if( gas::Data::hSplash )
{
ShowWindow( gas::Data::hSplash, SW_SHOW );
SendMessage( gas::Data::hSplash, WM_COMMAND, MAKESHIFT_TIMER, 0 );
}

if( CFG->GetShowWelcomePrompt() )
{
gas::CreateWelcomeDlg( hwnd );
if( !gas::Data::hWelcome )
MessageBox( NULL, "Error: Failed to create the Welcome Prompt GUI", "System Error", MB_OK|MB_ICONERROR );
}
return 0;
}

From one of the dialog headers...

case BUT_DATASRC_ACTIVATE_ONE:
{
// which one do they want to activate
unsigned int index = (unsigned int)SendMessage( GetDlgItem(hwnd, LST_DATASRC_DEFINED_SRC), LB_GETCURSEL, 0, 0 );
if( index >= 0 && index < DAT->GetDataSourceCount() )
{
gas::DataSource * ds = DAT->GetDataSource( index );
ds->active = true;
PopulateListBoxes( hwnd );
}
else
{
MessageBox( NULL, "You must select a data source before you can activate it", "Application Error", MB_ICONERROR|MB_OK );
}

processed = TRUE;
break;
}

Blake Miller4-Jan-05 8:51

Blake Miller

4-Jan-05 8:51

I usually NEVER pass in NULL as the first argument. Just for grins, try using the desktop window retreived with the GetDesktopWindow() function and see if that works for you.

realloc4-Jan-05 11:51

4-Jan-05 11:51

Hey Blake...

Thanks for the reply. I did as you instructed and and expereinced the exact same behavior.

Regarding the HWND arg, I typically pass in the handle of the GUI invoking the MessageBox(), but in an attempt to solve this I was pouring through Petzold, and one of the things he notes is that NULL makes it so that the MessageBox() isn't owned by anyone. I have been thinking I have some sort of message pump issue with the message making its way to the main window, so I thought I'd try eliminating ownership.

Honestly, I am at a loss... I have been comparing this code to half a dozen of apps I've written and I just can't find a difference. I invoke MessageBoxes from dialogs all the time.

Thanks for taking a look and adding some input

Dave

Blake Miller4-Jan-05 12:07

Blake Miller

4-Jan-05 12:07

Generally, invoking the message boxes from dialogs is NOT a problem.
What I am beginning to suspect is that if this current work is done when your application is starting up, you don't have a message pump for your program's primary thread yet. Microsoft's most recent guidelines and documentation infer that a thread does not necessarily have a message pump associated with it. A message pump is not created until the first call that would post, send, or attempt to retreive a message is made. You now might try putting a blank PeekMessage at the beginning of your program, using NULL as the 'window handle' to see if that will help your program get a message pump started. Then the message boxes might work after that call has been made.
A program's primary thread normally gets the message pump started when it first enters the get/translate/dispatch message loop. Anyway, it is just an idea of what I would be trying at this point to make it work.

realloc4-Jan-05 13:56

4-Jan-05 13:56

Hi Blake...

This was a good thought, I was hopeful. I tried at the very begginging, after the window creation and in the WM_CREATE... nada.

I did however take a cue from you post. After the failed attempt with the peek, I removed all calls from the WM_CREATE, let the main window complete (let it get a WM_SIZE and WM_PAINT). Added a menu and then invoked the dialogs via the menu after the main window had time to process a few messages. The behavior was unchanged.

I've been running diff after diff trying to find where I strayed from past projects and just can't find it. So I am thinking that I should start a new project and just rebuild piece by piece until I find where things go to hell. Instead of my template, I'll copy a project that works and edit it as needed to get it going.

Thanks for all the input, it was GREATLY appreciated!

Dave

realloc5-Jan-05 13:49

Problem with CRichEditCtrl

5-Jan-05 13:49

Just to follow up on this issue...

I fixed it, but still havn't solved it.

I created another project with my templates and got that working as normal. I then went back to the original project and commented out the entire main file.

I cut and pasted in the main file from the new project, made sure it still worked, and then proceeded to cut and paste my original code back into place line by line.

Esentially I am back to my original code, byte for byte unchanged, but it works... ??????????

I am 1000% confused, have never seen anything as annoying as this, but I am back in business again which is the most important thing for now.

Thanks for all your help!

Dave

Neelesh K J Jain4-Jan-05 0:27

Neelesh K J Jain

4-Jan-05 0:27

Hello Friends,
I had been posting my problems for the system beep and finally after alots of experiments I found the person who was responsible for the beep sound. It was the Clear() member function of the CRichEditCtrl class.
Now please can anybody tell why this member function is giving a beep sound (Default Beep) of the system properties.

Thanks in advance.

Neelesh K J Jain.

David Crow4-Jan-05 2:42

David Crow

4-Jan-05 2:42

At what point is the Clear() method getting called?

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

Neelesh K J Jain4-Jan-05 2:47

Neelesh K J Jain

4-Jan-05 2:47

At the time of OnInitialUpdate() member function. I had used CFormView class where I am having the OnSize() member function also. What I observed is If I include the OnSize() member function then the beep is coming otherwise the beep won't come. But Main problem is that OnSize() member function is also required.

David Crow4-Jan-05 5:28

David Crow

4-Jan-05 5:28

I'm not able to reproduce this problem. In a new SDI project with the view derived from CFormView, I added a rich edit control to the dialog template. Running the program produces no beep. What else do I need in order for the beep to occur?

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

Neelesh K J Jain4-Jan-05 16:49

Neelesh K J Jain

4-Jan-05 16:49

After creating the SDI, Add OnSize() member function, OnPaint() member function don't do anything in these functions and I require these member function also. Then the beep will come.

can any body tell me any software to check memory leak

David Crow5-Jan-05 2:30

David Crow

5-Jan-05 2:30

OnSize() and OnPaint() methods were added. As I suspected, no beep occurred.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

arus20044-Jan-05 0:13

arus2004

4-Jan-05 0:13

hi,
i am a vc++ programmer and i come across memory leak problem many times thus i want to know if any good software available that can check the pogram and tell me how many bytes the program is leacking memory on a perticular event, or can tell me exectly how much memory a process is tacking at runtime,

wisdoys taskmanger also tell us memoy usage in kbs but i will prefer if any softwre tels us in bytes + i dont think task manager is as reiable as i want cause when i use it, it gives different data for different occurence of same event or callin same function at different times

thanks

Re: can any body tell me any software to check memory leak

Neville Franks4-Jan-05 0:28

Neville Franks

4-Jan-05 0:28

Are you using the CRT Debug library functions?

See: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vccore98/html/_crt__crtsetdbgflag.asp[^] and http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vccore98/html/_crt_debug_functions.asp[^]

I also find Glowcode www.glowcode.com usefull.

Neville Franks, Author of ED for Windows www.getsoft.com and Surfulater www.surfulater.com "Save what you Surf"

Re: can any body tell me any software to check memory leak

Maximilien4-Jan-05 0:32

Maximilien

4-Jan-05 0:32

(assuming you are using Visual Studio )

before running of to buy a software, use what's available from VC++, first, be sure to run in debug mode, then, use the predefined macro DEBUG_NEW to replace new, and _malloc_dbg to replace malloc.

those 2 things will help you get a better view at what's going on with memory allocation.

If you really want to go deeper and find other potential problems, try either purify or boundschecker, both work well.

Maximilien Lincourt
Your Head A Splode - Strong Bad

Re: can any body tell me any software to check memory leak

Martin Koorts4-Jan-05 1:01

Martin Koorts

4-Jan-05 1:01

As somebody else already mentioned, the MFC is a good enough for most purposes. By default an MFC app will show leaks when your application exists, but if you want to track memory leaks over a shorter period, you can use the CMemoryState MFC class - which is the what the default behaviour employs.

HTH

Martin

Fatal Link Error: LNK:1201

Pearl M3-Jan-05 22:59

Pearl M

3-Jan-05 22:59

Hi,

I am building a project (where multiple dsp's Debug Info is set as Program Database for Edit & Continue) using VC++ editor.At the time of linking I am getting a linker error (LNK1201)

LINK : fatal error LNK1201: error writing to program database "prj.pdb" ; check for insufficient disk space

I found the root cause of the problem as below.
" There is a limit of 4096 modules (.obj files) in a PDB file. The file also has a total size limit of approximately 64 MB - From MSDN"

Here my prj.pdb file size exceeds 64 MB. Now my query is, Is there any way to increase the size of this file? Or I have to set the Debug Info as Line Numbers only for some DSP's. So that the size of the file will be decreased.

Thanks in Advance.

Regards,
Pearl

Re: Fatal Link Error: LNK:1201

Rajesh match3-Jan-05 23:52

Rajesh match

3-Jan-05 23:52

clean and rebuild the project

or delete pdb file and buld

GDI+ Bitmaps in an Array

rh0053-Jan-05 22:35

rh005

3-Jan-05 22:35

Hello,

is it possible to create GDI+ Bitmap objects in an array? Everywhere else are code examples like this one:

Bitmap myPNG(L"gfx/spiral.png");
graphics.DrawImage(&myPNG, 150, 200);

How can myPNG be an array?

Bitmap myPNG[10];

This will produce an error C2512: no appropriate default constructor available.

Any ideas?

Thanks in advance!

rh0053-Jan-05 23:56

rh005

3-Jan-05 23:56

Found it: by using the class described in this article: Loading JPG & PNG resources using GDI+ this works as it should.

Still, if anyone knows a better way, please let me know.

Ryan Binns4-Jan-05 2:55

Ryan Binns

4-Jan-05 2:55

rh005 wrote:
How can myPNG be an array?

Use an array of pointers and new each of them separately. Make sure you delete them afterwards though.

Ryan

"Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

rh0054-Jan-05 3:04

rh005

4-Jan-05 3:04

I am writing a simple, dialog-based application. I thought to use OnInitDialog to create all the image objects and be able to use them in OnPaint.

This will not work because the objects are discarded at the end of OnInitDialog.

What can I do? (Looks more like a C++ problem and not a GDI+ issue Smile | :)