C / C++ / MFC

CCriticalSection Multi-entry problem

5-Mar-13 0:30

Varadha Raj wrote:
What is the best choice for desktop application development.

There is no "best" choice, there are merely different solutions. The best one is the one that most closely offers a solution to your requirements: Win32, MFC, Windows Forms, WPF etc., it is up to you to decide which one to go with. However, you seem confused about the difference between desktop apps and web apps, so you should decide first which of those is necessary for you.

Use the best guess

yu-jian4-Mar-13 19:34

yu-jian

4-Mar-13 19:34

When lock the CriticalSection, the same thread can enter this CCriticalSection more than once at the same time.
How to avoid this problem?

Reading AVI file.

ashwath19794-Mar-13 19:04

ashwath1979

4-Mar-13 19:04

Hi All,

I have a compressed AVI file.

Can i use OPENCV to decompress the AVI file and read each frame in it?

OR should i go for a library like FFMPEG?

Can i used FFMPEG functions inside a MFC application to read AVI files?

Please help me in this.

Thanking you in advance.

Regards,
ashwath.

CFileDialog Problem breakpoint int 3

ForNow4-Mar-13 8:14

4-Mar-13 8:14

Hi,

I am having a lot of problems displaying the CFileDialog modal dialog box

after much research I have noticed many examples of the CfileDialog with Just 1 paramter

and then a DoModal e.g. CFileDialog mydialog(TRUE); mydialog.DoModal();

The problem I am encurring is when step to the mydialog.DoModal(); a breakpoint is hit "int 3"

and I get a access exception

has anyone had this problem trying to use a CFileDialog

Thsnks

Albert Holguin4-Mar-13 17:31

Albert Holguin

4-Mar-13 17:31

CFileDialogs are pretty much as simple as it gets... with that said, your question doesn't make a ton of sense. What's error that you're getting exactly? Is it a breakpoint or a assertion that's stopping execution?

Place applicable code and maybe I can get a better idea as to what you're doing wrong.

ForNow5-Mar-13 2:09

5-Mar-13 2:09

That exactly the point I had the contructer coded with filers window title etc.

but this code

C++

CFileDialog mydialog(TRUE);

		mydialog.DoModal();

should work

This what happens when I step to mydialog.DoModal();

The code hits a break point
and later on get a access violation
doing a Call Stack at this point seems that mscowrks.dll is executing
I moved this code to the beginng of CWinApp::Initinstance
so Its one the first things I do and still I have problem

ASM

000007FEFD223C6A  nop  
000007FEFD223C6B  nop  
000007FEFD223C6C  nop  
000007FEFD223C6D  nop  
000007FEFD223C6E  nop  
000007FEFD223C6F  nop  
000007FEFD223C70  xchg        ax,ax  
000007FEFD223C72  int         3  
000007FEFD223C73  ret  
000007FEFD223C74  nop  
000007FEFD223C75  nop  
000007FEFD223C76  nop  
000007FEFD223C77  nop  
000007FEFD223C78  nop

Albert Holguin5-Mar-13 10:00

Albert Holguin

5-Mar-13 10:00

ForNow wrote:
mscowrks.dll is executing

You're probably compiling this with some odd options, that's part of .Net (I believe), which you shouldn't be using at all on a C++/MFC application. I would guess your problem is not the code but the way you configured the project.

ForNow5-Mar-13 10:15

5-Mar-13 10:15

Thanks

that makes sense

Richard MacCutchan4-Mar-13 23:04

4-Mar-13 23:04

Assuming this is a continuation of your previous problem, I already suggested this[^], and similarly tried to explain, here[^], about the correct use of casts in C. Randomly changing parameters or removing them altogether is no substitute for making full use of both documentation and debug information.

Use the best guess

ForNow5-Mar-13 2:12

5-Mar-13 2:12

I did that and I still encountred the problem breakpoint followed by access violation

bottom line till me if I right

CFileDialog.mydialog(TRUE);

mydialog.DoModal(TRUE);

Should work as it would take default paramters correct ?

Richard MacCutchan5-Mar-13 3:20

5-Mar-13 3:20

ForNow wrote:
Should work as it would take default paramters correct ?

Not necessarily, as we do not know what else your code is doing. As I said before, read the documentation[^] and carefully check against your code. Also ensure that your project has been completely rebuilt to ensure no undiagnosed compiler errors remain.

Use the best guess

ForNow5-Mar-13 4:57

5-Mar-13 4:57

I'll re-read the doc

but

1) I got s clean build

2) this is the first thing in CWinApp::InitInstance

thank you

Richard MacCutchan5-Mar-13 5:59

5-Mar-13 5:59

There must be something wrong with your system that we are not aware of. Does this application run correctly if you do not use the CFileDialog?

Use the best guess

ForNow5-Mar-13 6:04

5-Mar-13 6:04

Yes it does

I am begining to think it must be something like file permissions

I live next to someone who worked for MicroSoft

He had a look at it once I'll ask him again

Thsnks

Richard MacCutchan5-Mar-13 6:18

5-Mar-13 6:18

That is most unlikely unless you have a Microsoft library that is corrupt or somehow unreadable.

I just reread some of your earlier posts and noticed :

ForNow wrote:
doing a Call Stack at this point seems that mscowrks.dll is executing

This, according to http://www.ehow.com/facts_7827759_mscorwksdll.html[^] is a .NET library, so I would be interested to know how that is getting connected to your app.

Use the best guess

David Crow5-Mar-13 6:05

5-Mar-13 6:05

ForNow wrote:

2) this is the first thing in CWinApp::InitInstance

The first thing? Maybe you are not giving the framework enough time to get everything ready. Perhaps putting the code someplace else (e.g., in response to a button click) would work better.

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

"Show me a community that obeys the Ten Commandments and I'll show you a less crowded prison system." - Anonymous

David Crow5-Mar-13 3:58

5-Mar-13 3:58

ForNow wrote:

mydialog.DoModal(TRUE);

This compiles?

David Crow5-Mar-13 4:03

5-Mar-13 4:03

I created an empty dialog-based app with the following change:

BOOL CDCDlg::OnInitDialog()
{
    CDialog::OnInitDialog();

    SetIcon(m_hIcon, TRUE);
    SetIcon(m_hIcon, FALSE);

    CFileDialog dlg(TRUE);
    dlg.DoModal();

    return TRUE;
}

It worked fine. Can you try something similar?

ForNow5-Mar-13 5:41

5-Mar-13 5:41

Tried the coce

the CfileDialog modeless displays it for an instance

and then i get a messagebox HERC_CMD encountered breakpoint

David Crow5-Mar-13 6:05

5-Mar-13 6:05

ForNow wrote:
Tried the coce

Where did you put it?

AbbeytekMD6-Mar-13 0:24

AbbeytekMD

6-Mar-13 0:24

There's a known problem with CFileDialog crashing although I can't remember the exact situations. Something to do with WINVER, I think. Anyway, you can test if this is what your problem is by creating the dialog on the stack and seeing if that stops the crash.

e.g.

CFileDialog* pFD = new CFileDialog(...);
pFD->DoModal();
.
.
delete pFD;

David Crow6-Mar-13 3:22

DirectShow is "no show so far" - need basic help

6-Mar-13 3:22

AbbeytekMD wrote:
There's a known problem with CFileDialog crashing

It was actually related to trying to use a CFileDialog object, which references m_pMainWnd, in a dialog-based app after the main dialog had been dismissed.

Vaclav_4-Mar-13 7:18

Vaclav_

4-Mar-13 7:18

OK I did embark into world of DirectShow and ditched VFW.
All the code samples here is way over my head for now.
I got as far as “using SDK to build basic DirectShow”. It is in one of many SDK 's “help doc” MS puts out here and there about DirectShow. I am suppose to build basic DirectShow application and use it as accessible debug library. I must be dense, but I cannot figure how to do it.
I do not need full blown sample code, there are plenty of them here, but gentle nudge into right direction in building from SDK sample would be appreciated.
Thanks for your time.
Cheers Vaclav

Re: DirectShow is "no show so far" - need basic help

Richard MacCutchan4-Mar-13 22:57