Re: How to run a thread as a member function of a class? - C / C++ / MFC Discussion Boards

make stacktrace or what calls DllCanUnloadNow?

ThinkingPrometheus14-Jun-05 4:21

14-Jun-05 4:21

hiho@ll

i have some trouble with a browser helper object

using Internet Explorer is no problem, but if i close IE i get an Error message (somethings reading from space which it isn't allowed)
i traced a bit using MessageBox Frown | :-(

and i found that the helper object destroys itself correctly using the WindowProc WM_Destroy event
then i get the error
and then DllCanUnloadNow is called successfully!

so what function is normally between the destroy windowproc and dllcanunloadnow?

thx@ll

Looking for Dialog Manager component for VC++ 7.

mlatimer14-Jun-05 4:00

mlatimer

14-Jun-05 4:00

Hi all

Wonder if you can help me, we are currently programing in MFC for our app which is dialog based - floating windows with 2 dialogs.

Our plans require more dialogs and a way to manage them on screen. What are are looking to do is create a "docking" architeture simlar to the toobars used in Photoshop (but at teh application top level).

Does anyone know of a component or toolkit that allows / helps build a dialog based UI with docking (allowing multiple dialogs to doc) / rollups etc ... or have any pointers or construction ideas?

All help very gratefully recived...

How to run a thread as a member function of a class?

Eytukan14-Jun-05 3:45

Eytukan

14-Jun-05 3:45

i used CWinThread.. the error message i'm getting is TrayDialog.obj : error LNK2001: unresolved external symbol "public: __thiscall CTrayDialog::CTrayDialog(void)" (??0CTrayDialog@@QAE@XZ).Please help..

CWinThread *pThread;

UINT Thread(LPVOID lp)
{
while(1)
{
AfxMessageBox("In Thread!");
Sleep(300);
}
return 0;
}

void CTrayDialog::TestThread()
{
CTrayDialog *obj;
obj=new CTrayDialog;
pThread=AfxBeginThread(Thread,obj);
}

thanks,
vivek

Re: How to run a thread as a member function of a class?

Bob Stanneveld14-Jun-05 4:08

Bob Stanneveld

14-Jun-05 4:08

Hello,

Add the following lines of code to TrayDialog.cpp:

CTrayDialog::CTrayDialog() : CDialog(NULL, CTrayDialog::IDD)
{
}

What you are doing here is add the unresolved external symbol (the default contructor), but I think that you need an other solution: change the following code:

void CTrayDialog::TestThread()
{
    CTrayDialog *obj;
    obj=new CTrayDialog; 
    pThread=AfxBeginThread(Thread,obj);
}

to:

void CTrayDialog::TestThread()
{
    CTrayDialog *obj;
    obj=new CTrayDialog(this); 
    pThread=AfxBeginThread(Thread,obj);
}

Hope this helps. Big Grin | :-D

Behind every great black man...
... is the police. - Conspiracy brother

Blog[^]

Re: How to run a thread as a member function of a class?

Eytukan14-Jun-05 1:43

Eytukan

14-Jun-05 1:43

thanks for ur help... but,
:(Compiling...
TrayDialog.cpp
D:\CLTRK\CLTRK02\TrayDialog.cpp(40) : error C2039: 'IDD' : is not a member of 'CTrayDialog'
d:\cltrk\cltrk02\traydialog.h(39) : see declaration of 'CTrayDialog'
D:\CLTRK\CLTRK02\TrayDialog.cpp(40) : error C2065: 'IDD' : undeclared identifier
D:\CLTRK\CLTRK02\TrayDialog.cpp(487) : error C2664: '__thiscall CTrayDialog::CTrayDialog(unsigned int,class CWnd *)' : cannot convert parameter 1 from 'class CTrayDialog *const ' to 'unsigned int'
This conversion requires a reinterpret_cast, a C-style cast or function-style cast
Error executing cl.exe.

MyTrayDlg.obj - 2 error(s), 0 warning(s)

what to do now bob? what's that IDD?

vivek

Re: How to run a thread as a member function of a class?

Bob Stanneveld14-Jun-05 1:49

Bob Stanneveld

14-Jun-05 1:49

Normally, when you use MFC and you create a dialog class, this class has a member called IDD. This is the dialog resource (how the windows looks and what controls are on it).

Since I don't know your classes, I don't know why you don't have them, but you can remove the line: : CDialog(...).

viveking wrote:

D:\CLTRK\CLTRK02\TrayDialog.cpp(487) : error C2664: '__thiscall CTrayDialog::CTrayDialog(unsigned int,class CWnd *)' : cannot convert parameter 1 from 'class CTrayDialog *const ' to 'unsigned int'

I must have switched the parameters. So the dialog resource comes second instead of first. If you are wondering what the other parameter is, it's the parent window of the dialog.

Behind every great black man...
... is the police. - Conspiracy brother

Blog[^]

Re: How to run a thread as a member function of a class?

Eytukan14-Jun-05 1:55

Eytukan

14-Jun-05 1:55

forget everything.... i'll come with a simpler example.. please wait. Confused | :confused:

vivek

Re: How to run a thread as a member function of a class?

Eytukan14-Jun-05 2:06

Eytukan

14-Jun-05 2:06

Though it looks primitive.. please dont ignore..
see the class test with its data member "text" and function "disp()"
i wanna access it from the Thread1 and Thread2..

#include <afxwin.h>
#include<afxext.h>
#include<stdio.h>

char fValue[10];
CWinThread *pThread1,*pThread2;

UINT Thread1(LPVOID lp)
{
CClientDC cdc(AfxGetApp()->m_pMainWnd);
int j=250;
for(int i=1;i<=600;i++)
{
cdc.TextOut(i,j,"Thread1");
cdc.SetBkColor(0x0009999);
Sleep(6);
strcpy(fValue,"Thread1");
Text = fValue; ///// I WANT TO ACCESS THE DATA MEMBER "TEXT" FROM CLASS TEST//
cdc.TextOut(500,500,Text);
}
disp();/// HOW TO ACCESS MEMBER FUNCTION "DISP" FROM CLASS TEST//
return 0;
}

UINT Thread2(LPVOID lp)
{

CClientDC cdc(AfxGetApp()->m_pMainWnd);
cdc.SetBkColor(0x0990009);
int j=280;
for(int i=1;i<=600;i++)
{
cdc.TextOut(i,j,"Thread1");
Sleep(5);
strcpy(fValue,"Thread2");
Text = fValue;///// I WANT TO ACCESS THE DATA MEMBER "TEXT" FROM CLASS "TEST"//
cdc.TextOut(500,500,Text);

}

disp();/// HOW TO ACCESS MEMBER FUNCTION "DISP" FROM CLASS TEST//
return 0;
}

class test
{
public:

CString Text;

void disp()
{
AfxMessageBox(Text);
}
};

CMenu cm;

class MyWindow: public CFrameWnd , public test
{
public:
MyWindow()
{
Create(0,"Threads of MFC");
}

void q()
{
PostQuitMessage(0);
}

void Threads()
{
AfxMessageBox("Starting....");
}
DECLARE_MESSAGE_MAP()
};

BEGIN_MESSAGE_MAP(MyWindow,CFrameWnd)
END_MESSAGE_MAP()

class MyWin:public CWinApp
{
public :

BOOL InitInstance()
{
MyWindow *x;
x=new MyWindow;
m_pMainWnd=x;

pThread1=AfxBeginThread(Thread1,x);
pThread2=AfxBeginThread(Thread2,x);

x->ShowWindow(SW_SHOWMAXIMIZED);
return 1;
}
};
MyWin App;

thanks bob,
vivek

Re: How to run a thread as a member function of a class?

David Crow14-Jun-05 2:20

David Crow

14-Jun-05 2:20

viveking wrote:
disp();/// HOW TO ACCESS MEMBER FUNCTION "DISP" FROM CLASS TEST//

Try:

UINT Thread2(LPVOID lp) 
{
    MyWindow *mw = (MyWindow *) lp;
    mw->disp();
    return 0;
}

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

Re: How to run a thread as a member function of a class?

Bob Stanneveld14-Jun-05 21:17

Bob Stanneveld

14-Jun-05 21:17

Hello,

Sorry for this late reply..

A couple of things:
<list>

You pass a pointer x, that points to a MyWindow object to the thread as parameter, but you don't use it in either of your threads..

You call AfxGetApp() to get the value of m_pMainWnd

Your main app window is x

MyWindow derives from Test
Thinking about all these things don't ring a bell? Anyway, what you want to achieve can be done in at least the following 2 ways:

static_cast<MyWindow*>(AfxGetApp()->m_pMainWnd)->Text;

static_cast<MyWindow*>(lp)->Text;

Hope this helps Big Grin | :-D

Behind every great black man...
... is the police. - Conspiracy brother

Blog[^]

Re: How to run a thread as a member function of a class?

Cedric Moonen14-Jun-05 1:57

Cedric Moonen

14-Jun-05 1:57

Can you post the header file of your class ? Please use formating tags (the code tag just above the emoticons).

Re: How to run a thread as a member function of a class?

Michael Dunn14-Jun-05 4:21

Michael Dunn

14-Jun-05 4:21

See the FAQ
6.1 Why can't I use a member function as a callback?[^]

--Mike--
Visual C++ MVP Cool | :cool:

LINKS~! Ericahist | 1ClickPicGrabber | CP SearchBar v2.0.2 | C++ Forum FAQ
Strange things are afoot at the U+004B U+20DD

Re: How to run a thread as a member function of a class?

Eytukan14-Jun-05 2:14

Eytukan

14-Jun-05 2:14

cedric, my program is too complex.. even i'm worn out looking at the code..
can u post a simple program which wil explain it clearly?
should i declare the thread inside the class? just like we do for member functions?
i.e
class test
{
public
UINT Thread(LPVOID lp);
}
??
do we have any alternative for CWinThread?

vivek

i'm Noosed down by the THREADS!!

Eytukan14-Jun-05 2:25

Eytukan

14-Jun-05 2:25

Solution for the thread

Eytukan15-Jun-05 6:11

Eytukan

15-Jun-05 6:11

bob,david,cedric,michael, and paul........
paul the link u gave is ultimate.. thank u so much. really resourceful.i think i wont be disturbing u guys again.. everything's there Smile | :)

The Thread Solution

It is almost always the case that you can use threads to do the job more easily. This is not without certain costs and hazards, but it ultimately is the better method.

Here's a solution to handling the invert-everything. Note that we have to move from the pure-C domain (which we interface to via a static method) to the MFC domain.

To the class (in this example, a CView-derived class), add the following declarations:

static UINT run(LPVOID p);
void run();
volatile BOOL running;
To start a thread, your handler does

void CMyView::doInvert()
{
running = TRUE;
AfxBeginThread(run, this);
}

UINT CMyView::run(LPVOID p)
{
CMyView * me = (CMyView *)p;
me->run();
return 0;
}

void CMyView::run()
{
for(int x=y = 0; running && y < image.height; y++)
for(int x = 0; running && x < image.width; x++)
changePixel(x, y);
running = FALSE;
}
The command to stop the thread is very simple:

void CMyView::OnStop()
{
running = FALSE;
}
That's all there is to it!
Laugh | :laugh:

vivek

Re: How to run a thread as a member function of a class?

Paul Steane14-Jun-05 19:28

Paul Steane

14-Jun-05 19:28

I suggest you have a look at Joseph M. Newcomer's articles on "Threads and Processes" at http://www.flounder.com/mvp_tips.htm[^]

please check out this link

Eytukan15-Jun-05 6:20

Eytukan

15-Jun-05 6:20

http://www.flounder.com/workerthreads.htm[^]

thank u so much guys,
vivek

Create an application to clear Heap Memory

Member 137164714-Jun-05 3:36

Member 1371647

14-Jun-05 3:36

My situation is where I have a java application which is using the heap memory (we tuned by Xms and Xmx settings). Even the memory is cleared by System.gc()the memory is not freed and is not retured back to OS. We are able to see the heap increasing as we run our application.
To free that memory what sort of approch i can do using C++ /VC++/VB. Can any one helpe in writting a program to do the same D'Oh! | :doh:

Re: Create an application to clear Heap Memory

David Crow14-Jun-05 1:35

David Crow

14-Jun-05 1:35

Jreko2003 wrote:
We are able to see the heap increasing as we run our application.

What are you using to verify this? If it's Task Manager, see here.

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

Re: Create an application to clear Heap Memory

Anonymous14-Jun-05 6:34

Anonymous

14-Jun-05 6:34

Jreko2003 wrote:
My situation is where I have a java application which is using the heap memory (we tuned by Xms and Xmx settings). Even the memory is cleared by System.gc()the memory is not freed and is not retured back to OS.

Memory is never returned back to OS. You can only re-use freed memory within the program.

Help Me! How to access a file with filename have space letters?

lewislewis_lewis14-Jun-05 3:35

lewislewis_lewis

14-Jun-05 3:35

we know we can access a file(dload, create, delete...) on a ftpsite
by some software, but i try to write a program with error for filename:...

The Codes i wrote can not found file "My Projectinfo.inf", Why?
Are there some way to access file has filname have space?

My_Fun()
{
...
pFtpConn = mysession.GetFtpConnection( my_ftpserver, my_user, my_pass );
CFtpFileFind finder(pFtpConn);
BOOL bWorking = finder.FindFile("/My Projectinfo.inf" );
...
}

Thanks!!!

Re: Help Me! How to access a file with filename have space letters?

David Crow14-Jun-05 1:28

David Crow

14-Jun-05 1:28

lewislewis_lewis wrote:
BOOL bWorking = finder.FindFile("/My Projectinfo.inf" );

If FindFile() returns FALSE, what does GetLastError() return?

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

error code is 18

lewislewis_lewis14-Jun-05 4:59

lewislewis_lewis

14-Jun-05 4:59

if( !bWorking )
{
DWORD errcode = GetLastError();

LPVOID lpMsgBuf;
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS,
NULL,
errcode, //GetLastError(),
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
(LPTSTR) &lpMsgBuf,
0,
NULL
);

MessageBox( NULL, (LPCTSTR)lpMsgBuf, "Error", MB_OK | MB_ICONINFORMATION );
LocalFree( lpMsgBuf );
}

the MessageBox dispaly :"There are no more files"

What is wrong?

Re: error code is 18

David Crow14-Jun-05 2:05

David Crow

14-Jun-05 2:05

Does your code work for files with no spaces in the name?

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

YES!

lewislewis_lewis14-Jun-05 5:26

lewislewis_lewis

14-Jun-05 5:26

YES, I tested it maney times.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.