C / C++ / MFC Discussion Boards

Re: whats going on??????

Ernest Laurentin25-Apr-02 5:17

Ernest Laurentin

25-Apr-02 5:17

I tried it and didn't see any crash!

double angle=3.0/10.0;<br />
  for(double i=0.0; i<360.0; i+=angle)<br />
  {<br />
    //do stuff<br />
     TRACE1("%f", i);<br />
   }

Look at the reason of the error, it is an exception error?
did you pass some invalid value to a math function (most of them will
return NaN value)?
The other thing I can say, debug (F9, F10, F11).

"Dirty hands lead to important discovery..." - Thomas Edison

Re: whats going on??????

Joaquín M López Muñoz25-Apr-02 6:43

Joaquín M López Muñoz

25-Apr-02 6:43

A significative difference is that in the latter case, the increment value is stored in the stack (at least in debug mode), while in the former it is a constant value directly fed to the ADD assembly instruction. So, I'd bet for your program somehow corrupting he stack (maybe writing out of bonds of some array?)

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: whats going on??????

Rajveer25-Apr-02 7:07

Rajveer

25-Apr-02 7:07

So how do I deal with something like that?

Re: whats going on??????

Joaquín M López Muñoz25-Apr-02 8:21

Joaquín M López Muñoz

25-Apr-02 8:21

To make sure, put something like this at the beginning of your for:

for(double i=0.0; i<360.0; i+=angle)
{
  assert(angle==3.0/10.0);
  ...
}

if the assert fires, then it is almost sure you're corrupting the stack. Check your indices, do a step-by-step run examining the exact moment when angle changes, etc.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

How can i destroy a window that doesn't want to? ;)

argaleen25-Apr-02 4:06

argaleen

25-Apr-02 4:06

Hi there,

I got a problem destroying a window. Just a short overview about what I'm doing:

I have a thread doing a loop and another thread showing a progress window. When the loop is done i want to send the other thread a message so that it closes (which is just working fine). My problem is that the user *could be* dragging the window right now when I Post the Quit message to UI thread and therefore the window remains open.

Any help of you guys would be appreciated very much!

Thanks,

Ruediger

It's never too early to try something really stupid.

Re: How can i destroy a window that doesn't want to? ;)

Ernest Laurentin25-Apr-02 5:02

Ernest Laurentin

25-Apr-02 5:02

Well that's because your UI thread is not processing any other message. Force processing
the other message by cancelling the "dragging" mode.
Question: when the user stops dragging the window, does the UI thread destroy it?
(it should, right?)
Hope this help you!

"Dirty hands lead to important discovery..." - Thomas Edison

Re: How can i destroy a window that doesn't want to? ;)

argaleen25-Apr-02 5:09

argaleen

25-Apr-02 5:09

Hi Ernest,

thanks for your reply. Unfortunately the window does NOT close after the user releases it, in fact the window is kept open and the thread stays alive for an undefined time!

Is there a way to stop the dragging mode? I suspect that the other messages are processed, otherwise the window would close after the user releases it...

Regards,

Ruediger

Re: How can i destroy a window that doesn't want to? ;)

Ernest Laurentin25-Apr-02 5:37

Ernest Laurentin

25-Apr-02 5:37

Okay, why not just destroy the window yourWindow.DestroyWindow();?
Sending a message with WM_DESTROY has the same effect. I suspect when you say
*dragging*, you mean the user is *moving* the window. In anyway, you should not
worry! if you need to destroy that window, just destroy it! (this is a progress
dialog, right?)
That should fix your problem.
Good luck!

"Dirty hands lead to important discovery..." - Thomas Edison

Re: How can i destroy a window that doesn't want to? ;)

argaleen25-Apr-02 23:08

argaleen

25-Apr-02 23:08

I tried that one too but it didn't help. The problem is that the UI thread was blocked and did not receive any messages but I found that solution now in case anybody encounters a similar problem:

in the destroy function of the calling thread I did the follwing:

DWORD dwProcessId = GetWindowThreadProcessId(m_hParentWnd,0L);

::AttachThreadInput(dwProcessId,m_pThread->m_nThreadID,TRUE);
::ReleaseCapture();

m_pThread->PostThreadMessage(WM_QUIT,0,0);

::AttachThreadInput(dwProcessId,m_pThread->m_nThreadID,FALSE);

And so it worked Smile | :)

Anyway, thanks for the help!!!

Regards,

Ruediger

Re: How can i destroy a window that doesn't want to? ;)

Ollie25-Apr-02 5:12

Ollie

25-Apr-02 5:12

Try using a 'SendMessage' instead of 'PostMessage', if you are unsure of the difference, post asynchronious and send message is synchronious....

the "PostMessage" function

Aviv Halperin25-Apr-02 3:56

Aviv Halperin

25-Apr-02 3:56

I want to post a message to a window by its handle.
how can i retrieve the handle of a window?(I need this handle to post the message using the function
BOOL PostMessage(
HWND hWnd,
UINT Msg,
WPARAM wParam,
LPARAM lParam );

thanks,
Aviv.

avivhal

Re: the "PostMessage" function

Jeremy Falcon25-Apr-02 4:04

Jeremy Falcon

25-Apr-02 4:04

GetWindow()<br />
FindWindow()<br />
FindWindowEx()<br />
GetDlgItem()

Jeremy L. Falcon
"The One Who Said, 'The One Who Said...'"
<nobr>
Homepage : Sonork = 100.16311
01000010011011110110001000100000011101110110000101110011
00100000011010000110010101110010011001010010111000000000

Read string at a certain point?

Aoife25-Apr-02 3:48

Aoife

25-Apr-02 3:48

Hello,

I need to read the following two lines from a .txt file.

Name John Doe
Number +12345

Then I must extract "John Doe" and "+12345" and send them to an edit box.
I tried using strtok() but it didn't work the way I want it to. Is there a way of starting at a particular point in the string? eg in "Name John Doe" at position 6.

Thanks,
Aoife

/********************************************/

FILE *stream;
stream = fopen( "number", "r" );

char bufLine1[30], bufLine2[30];

fgets(bufLine1, 30, stream);
fgets(bufLine2, 30, stream);

char *pNext1 = ?????(bufLine1, ??);
char *pNext2 = ?????(bufLine2, ??);

strcpy(bufLine1, pNext1);
strcpy(bufLine2, pNext2);

SendDlgItemMessage(IDC_BOX1, EM_REPLACESEL, FALSE, (LPARAM)bufLine1);
SendDlgItemMessage(IDC_BOX2, EM_REPLACESEL, FALSE, (LPARAM)bufLine2);

fclose( stream );

Re: Read string at a certain point?

Michael P Butler25-Apr-02 3:50

Michael P Butler

25-Apr-02 3:50

Have a look at CString's Mid and Right functions.

Michael Smile | :)

Re: Read string at a certain point?

Alexandru Savescu25-Apr-02 3:54

Alexandru Savescu

25-Apr-02 3:54

You can use std::string and std::ifstream like this;

ifstream in ("number");
string dummy, Name, Number;
in >> dummy >> Name;
int >> dummy >> Number;

Best regards,
Alexandru Savescu

Re: Read string at a certain point?

Tim Smith25-Apr-02 3:57

Tim Smith

25-Apr-02 3:57

If you know that the text starts in column 6, then

char *pNext1 = &bufLine1 [6];

will work just fine.

Tim Smith

I know what you're thinking punk, you're thinking did he spell check this document? Well, to tell you the truth I kinda forgot myself in all this excitement. But being this here's CodeProject, the most powerful forums in the world and would blow your head clean off, you've got to ask yourself one question, Do I feel lucky? Well do ya punk?

Re: Read string at a certain point?

Aoife25-Apr-02 4:49

Aoife

25-Apr-02 4:49

This worked perfectly, Thanks!

who can help me?

Atilla Selem25-Apr-02 3:08

Atilla Selem

25-Apr-02 3:08

hi!,
i want to insert text into a ListBox on the Main Dialog of my Application and update my dialog screen while program is in a function which resides in another Cpp file of my project. i call Main Dialog function, which updates text, in that function (in Cpp) and program suddenly terminates when it tries to add string into ListBox.
How will i reach the memory resource of Main Dialog Controls when i'm in another cpp?
While i was debugging i saw that there is no handle assigned to ListBox when Main Dialog function was called inside the other function in that Cpp.

Thanks for ur help
Atilla Selem

willing to learn and teach

Re: who can help me?

Michael P Butler25-Apr-02 3:28

Michael P Butler

25-Apr-02 3:28

You'll need to post the portion of your code that is going wrong.

I'm guessing that the Window for the Listbox hasn't been created at the point you are trying to update it.

Are you calling the function on the same instance of the dialog class?

Michael Smile | :)

Re: who can help me?

Atilla Selem25-Apr-02 3:54

Atilla Selem

25-Apr-02 3:54

i have just found the mistake that i did (shown below). i had forgetten to uncomment line (2) so i couldn't have reached any control of my Dialog that i want to update...

Thanks for ur interest..
Atilla Selem

// SockDlg.cpp : My implementation file
(1) CSockDlg* pSockDlg;
(2) pSockDlg=(CSockDlg*)(CWnd::FromHandle(m_hWnd));

// MulticastSocket.cpp : Cpp that i call my dialog funtion to update text in
my ListBox;

extern CSockDlg* pSockDlg;
{
..
..pSockDlg->OnReceive();
}

-----> m_ctlRecvd.AddString(strRecvd); // which resides in OnReceive() in SockDlg

and it has worked!...

willing to learn and teach

difference between handle & instance

Aviv Halperin25-Apr-02 3:02

Aviv Halperin

25-Apr-02 3:02

What is the difference between the handle of a window(type HWND) and the instance (type HINSTANCE)?
thanks

avivhal

Re: difference between handle & instance

Tim Smith25-Apr-02 3:31

Tim Smith

25-Apr-02 3:31

One is the handle to a window and the other is the handle to a EXE or DLL loaded in memory.

Tim Smith

I know what you're thinking punk, you're thinking did he spell check this document? Well, to tell you the truth I kinda forgot myself in all this excitement. But being this here's CodeProject, the most powerful forums in the world and would blow your head clean off, you've got to ask yourself one question, Do I feel lucky? Well do ya punk?

Re: difference between handle & instance

moliate25-Apr-02 4:44

moliate

25-Apr-02 4:44

HINSTANCE and HMODULE is the real address inside a processpace. HWND is just an internal reference number. It is not generally safe to cast handle types to anything else.

/moliate

SetPixelColor for 8-bit bmp

chen25-Apr-02 2:41

chen

25-Apr-02 2:41

Dear all,

I seen many classes about bmp image.
But there seems a few cases in dealing with
setpixel for 8-bit bmp file.

Based on my code as follows, would you please
tell me how to setpixelcolor for 8-bit bmp image?

class CDraw8
{
public:
CDib *m_dib; // the DIBSECTION
COLORREF m_pal[256];
BYTE *m_adr; //start-address of image-data
int *m_yadr; // array with line-start-addresses

CDraw8();
BOOL Init(CDib* dib);

// read RGB color, using pixel-value as index to palette

COLORREF GetPixelColor(int x, int y)
{return m_pal[m_adr[m_yadr[y]+x]];}

void SetPixelColor(int x, int y, COLORREF col);
//???? How to do this //

COLORREF GetPixelIndex(int x, int y)
{return m_adr[m_yadr[y]+x];}

SetPixelIndex(int x, int y, BYTE index)
{ m_adr[m_yadr[y] + x] = index;}
}

Thanks in advance!

xyz

Re: SetPixelColor for 8-bit bmp

Mike Zinni25-Apr-02 3:14

Mike Zinni

25-Apr-02 3:14

I've been doing alot of research into Device Independant Bitmaps lately, and everything that I've read states the the pixel data stored in an 8bit bitmap image isnt actually color data at all. The data is merely an index into that bitmap's color palette. So, to change a particular pixel's color, you have 2 choices:

1) Change that pixel's index into the color palette.
OR
2) Change the RGB values in the color palette for that pixel's index.

I would suggest the first option because it only affects the pixel you would like to change. Changing an entry in the color palette could cause other pixels to change color also.

I am by no means an expert on this topic, I've just been doing alot of reading about this stuff lately and I thought I might be able to help. Hope I did.

-Mike Zinni
Software Engineer
email: mzinni@rimail.com
AIM: zin9999

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