C / C++ / MFC

13-Jan-03 23:35

Hi,

I have a audio player that is skinned. There are 4 seperate regions (different states in the player). I create these regions before hand on program start up. My problem is that when I try to set a region that has already been used before the SetWindowRgn function fails (I'm guessing because windows deleted it or something)

I want to avoid creating the region on the fly because it takes a second or so to create the region from the bitmaps that I use for skinning.

Is there anyway to stop windows from deleteting the region after you set the window region to a different one.

Thanks

jhwurmbach13-Jan-03 23:54

jhwurmbach

13-Jan-03 23:54

Ceri wrote:
Is there anyway to stop windows from deleteting the region after you set the window region to a different one

No. MSDN states:
After a successful call to SetWindowRgn, the operating system owns the region specified by the region handle hRgn. The operating system does not make a copy of the region, so do not make any further function calls with this region handle, and do not close this region handle

But you can use CRgn::CopyRgn() to make a local copy of your region, before you feed it to the API.

My opinions may have changed, but not the fact that I am right.

Ceri14-Jan-03 0:06

14-Jan-03 0:06

Is the CopyRgn function of the CRgn class fast enough so that it does not show a delay.

jhwurmbach14-Jan-03 0:08

jhwurmbach

14-Jan-03 0:08

Sorry, I have no idea.
Just remember to tell here if you find out Wink | ;)

Good luck with you project!

My opinions may have changed, but not the fact that I am right.

Hans Ruck14-Jan-03 1:17

Hans Ruck

14-Jan-03 1:17

It should be. Anyway, i think this API must be the fastest:

DWORD dw;
RGNDATA *lp;
HRGN hRgnCopy;

dw=::GetRegionData(hRgn, sizeof(RGNDATA), NULL);
lp=(RGNDATA *)(new char[dw]);
hRgnCopy=::ExtCreateRegion(NULL, dw, lp);
delete lp;

rechi

[OT] Determine the compiler-version

Joaquín M López Muñoz14-Jan-03 0:02

Joaquín M López Muñoz

14-Jan-03 0:02

Ummm. Maybe you can copy the region (CopyRgn) before passing it on to the windows with SetWindowRgn so that you have always a fresh copy to work with.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

tabor2513-Jan-03 23:09

tabor25

13-Jan-03 23:09

Hello,

maybe this is a little off-topic, but i don't know where to post this problem - sorry. I need to determine if my source-code is compiled by vc60 or .net, because i have to include different header-files depending on the compiler-version. I want to do it in a way like this :

#ifdef _VC60
#include <..\src\afximpl.h>
#else
#include <..\src\mfc\afximpl.h>
#endif

I think that there must exist a global constant or variable that describes the compiler-version. But what is the name of this constant or variable (it's not _VC60 Wink | ;-)

).

Best regards

tabor25

Re: [OT] Determine the compiler-version

Oliver Anhuth13-Jan-03 23:20

Oliver Anhuth

13-Jan-03 23:20

You can get the compiler version with _MSC_VER. Look into the online help for the possible values.

However from your example I guess that you really want to use _MFC_VER which gives you the MFC version (>= 0x0700 for MFC 7 or higher).

Oliver

Re: [OT] Determine the compiler-version

tabor2513-Jan-03 23:53

tabor25

13-Jan-03 23:53

Thank you very much, Oliver. I will use the online-help to figure out the rest.

Best regards

tabor25

First-chance exception: Mem violation

boon kian13-Jan-03 22:56

boon kian

13-Jan-03 22:56

Hi,

can anyone help me with this prob ??? I am at a total lost

I have several pointers (using them as matrix) and i have always allocate mem to them using the "new" operator. However i encounter a strange problem with one of them (temp). Whenever my program trys to access the pointer 'temp' up to a location, it would generate an "First-chance exception: 0xC00000005: Access violation" error.

an eg of the code is like this:

double * temp

temp = new double (5000);

for (i = 0; i < 5000; i ++)
{
temp[i] = x*y;
}

I use breakpoints and see that the index of temp from 1 to 2577 is valid. However when i > 2578 all the values are invalid ("CXX0030: Error: expression cannot be evaluated") and hence causing my program to hit the ""First-chance exception: 0xC00000005: Access violation" error. This seems so strange to me and i am at a lost of what to do......

Can anyone tell me why is it so ?? and how can i solve this problem??
Thank you very much for your kind attention !!

Re: First-chance exception: Mem violation

Hans Ruck13-Jan-03 23:11

Hans Ruck

13-Jan-03 23:11

Must be:
temp = new double [5000];

rechi

Re: First-chance exception: Mem violation

boon kian13-Jan-03 23:17

boon kian

13-Jan-03 23:17

Hi rechi,

Really thanx a lot ... I guess i made a silly typo without realizing !! You save my day

bk

endless loop interruption

geluionescu13-Jan-03 22:46

13-Jan-03 22:46

Hello everybody,

My task is to interrupt a job (click on a button) that takes a lot of time for execution (a kind of endless loop). This code is in a DLL.
I tried different methods without success.

If the code is executed in the same thread, I can solve this problem with the ::PeekMessage() function.
Is the DLL executed in a different thread?

Can you help me?

Thanks,
Gelu

Joaquín M López Muñoz13-Jan-03 23:48

Joaquín M López Muñoz

13-Jan-03 23:48

In principle, DLL code is executed in the same thread as the EXE that invokes it, unless the DLL launches a secoondary thread on purpose.
Anyway, I'm curious about how you plan to terminate the llop using PeekMessage. Good luck.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

geluionescu14-Jan-03 1:08

14-Jan-03 1:08

Obviously, when I work in a executable my code seems like this:

fct()
{
.... init loop ...
MSG msg;

while(!(::PeekMessage(&msg, GetDlgItem(IDC_STOP)->m_hWnd, 0, 0, PM_NOREMOVE))
{
...... do a step ...
}
}

where IDC_STOP is a button.

If I put the same code in a DLL

fct()
{
.... init loop ...
MSG msg;

while(!(::PeekMessage(&msg, 0, 0, 0, PM_NOREMOVE))
{
...... do a step ...
}
}

The GUI freezes and I have to use the task manager to kill the task

Thanks,
Gelu

Ceri14-Jan-03 0:04

14-Jan-03 0:04

Hi,

First create a new thread for your endless loop function. Then the first line of the thread execute the following

[code]
PeekMessage(&msg, NULL, WM_USER, WM_USER, PM_NOREMOVE)
[/code]

This will force the OS to create a non windowed message loop. Inside your loop you can the use PeekMessage or GetMessage to receive messages for that thread. Obviously the hWnd member of the MSG struct will contain NULL because is has no window.

To post a message to the thread message loop use PostThreadMessage. This will fail if you haven't created the message loop at the start of the thread

Hope this helps

Ceri

geluionescu14-Jan-03 3:21

14-Jan-03 3:21

Hi Ceri,

My experience on creating threads in Windows system is very limited. Can you recommend me some code?

Thanks,
Gelu

Ceri14-Jan-03 4:55

14-Jan-03 4:55

Try this

[code]

#include "stdafx.h"

#define CUSTOMSTOPMSG WM_USER + 1

DWORD WINAPI ThreadProc(LPVOID lpParameter);
void StartThread();
void StopThread();

//the thread ID. Must give this ID to PostThreadMessage
DWORD dwThreadID = 0;

//this function is the thread function - contains the infine loop
DWORD WINAPI ThreadProc(LPVOID lpParameter)
{

MSG msg;
int iRetVal = 1;
PeekMessage(&msg, NULL, WM_USER, WM_USER, PM_NOREMOVE); //forces creation of non windowed message loop

while(!(PeekMessage(&msg, NULL, CUSTOMSTOPMSG, CUSTOMSTOPMSG, PM_REMOVE)))
{
//....do processing here

};

//.... do clean up here

return(iRetVal);

}

//execute this function from your standard thread
void StartThread()
{

HANDLE hThread;

//you can use this to pass a parameter to your thread
//(usualy a pointer to a struct or some other kind of user data)
LPVOID pParam = NULL;

hThread = CreateThread(NULL,0,ThreadProc,pParam,0,&dwThreadID);
}

void StopThread()
{

//obviously wParam and lParam in the PostThreadMessage could be some value also

if(dwThreadID)
PostThreadMessage(dwThreadID,CUSTOMSTOPMSG,0,0);

}

[/code]

Call StartThread when you want to initialize the loop and StopThred when you want to stop (I guess you would use your button for this)

Let me know how you get on

geluionescu14-Jan-03 5:45

14-Jan-03 5:45

Many thanks Ceri. It works perfectly.

Gelu

Ceri14-Jan-03 22:06