Re: threadcreation - C / C++ / MFC Discussion Boards

Re: CDC MoveTo(int,int)

subramanyeswari11-Jun-08 2:52

subramanyeswari

11-Jun-08 2:52

thank you

Re: CDC MoveTo(int,int)

Jijo.Raj11-Jun-08 1:55

Jijo.Raj

11-Jun-08 1:55

Need the windows api version of CDC::MoveTo()? Check MoveToEx() function.

Regards,
Jijo.

_____________________________________________________

http://weseetips.com[^] Visual C++ tips and tricks. Updated daily.

Re: CDC MoveTo(int,int)

Hamid_RT11-Jun-08 2:04

Hamid_RT

11-Jun-08 2:04

Do you need to MoveTO and LineTo? see this example of MSDN:
void Marker(LONG x, LONG y, HWND hwnd)
{
HDC hdc;

hdc = GetDC(hwnd);
MoveToEx(hdc, (int) x - 10, (int) y, (LPPOINT) NULL);
LineTo(hdc, (int) x + 10, (int) y);
MoveToEx(hdc, (int) x, (int) y - 10, (LPPOINT) NULL);
LineTo(hdc, (int) x, (int) y + 10);

ReleaseDC(hwnd, hdc);
}

Re: CDC MoveTo(int,int)

achainard11-Jun-08 2:09

achainard

11-Jun-08 2:09

On Proc or Message loop add hook on WM_PAINT

switch ( Message )
{
case WM_PAINT: {
PAINTSTRUCT ps;
ZeroMemory ( &ps, sizeof ( PAINTSTRUCT ));
HDC hDc = BeginPaint ( /*handle of your window*/, &ps );

MoveToEx ( hDc, 0, 0, NULL );
LineTo ( hDc, 10, 10 );

EndPaint ( /*handle of your window*/, &ps );
}
return 0L;
}
}

You can adjust color with HPEN and SelectObject.

Bye...

...

threadcreation

Mohanraj D11-Jun-08 1:32

Mohanraj D

11-Jun-08 1:32

how to craete a thread in MFC????and implement multithreading,i need to implement a seperate thread of operation inside a button click,what should be done,and createthread() doesn't work

Raja

Re: threadcreation

Jijo.Raj11-Jun-08 1:39

Jijo.Raj

11-Jun-08 1:39

Check this -
http://www.codeproject.com/KB/threads/threads_and_mfc.aspx[^]

Mohanraj D wrote:
and createthread() doesn't work

Check the error code by adding @err,hr in the watch window. You'll get the reason why its getting failed. If you still have trouble, the post the relevant code.

Regards,
Jijo.

_____________________________________________________

http://weseetips.com[^] Visual C++ tips and tricks. Updated daily.

Re: threadcreation

Mohanraj D11-Jun-08 2:22

Mohanraj D

11-Jun-08 2:22

my application is for windowsmobile...is there any different methodology for that

Raja

Re: threadcreation

Jijo.Raj11-Jun-08 2:56

Jijo.Raj

11-Jun-08 2:56

Mohanraj D wrote:
my application is for windowsmobile..

You can use AfxBeginThread() function. My msdn documentation says that its supported in "Pocket PC". So i think you can use it.

Mohanraj D wrote:
is there any different methodology for that

Ofcourse

. For instance,
1)

AfxBeginThread()<br />

2) CreateThread()
3) _beginthread(), _beginthreadex()
4)

SHCreateThread()<br />
<br />

But, since your target platform is Windows Mobile, all the specified functions may not be available.

Regards,
Jijo.

_____________________________________________________

http://weseetips.com[^] Visual C++ tips and tricks. Updated daily.

Re: threadcreation

CPallini11-Jun-08 1:39

CPallini

11-Jun-08 1:39

Mohanraj D wrote:
how to craete a thread in MFC????and implement multithreading

Do you know this site has a search engine for articles [^]?

Mohanraj D wrote:
need to implement a seperate thread of operation inside a button click,what should be done,and createthread() doesn't work

CreateThread works, of course.
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

Re: threadcreation

achainard11-Jun-08 2:02

achainard

11-Jun-08 2:02

Hi,

There's a class call CWinThread (for more information look on msdn).
-> MFC is a good lib only for Graphic User Interface, for the rest to not use it...

Perso i prefere use the win32 version :

// H.
HANDLE m_hThread;
DWORD m_dwThreadId;
static DWORD WINAPI ThreadProc( LPVOID pParam );
inline bool ThreadFuntion ();

// CPP.

xxxxxxx:xxxxxxxx () :
hThread ( NULL )
, m_dwThreadId ( 0 )
{
}

xxxxxx::OnClick ()
{
hThread = CreateThread(
NULL, // default security attributes
0, // use default stack size
ThreadProc, // thread function
this, // argument to thread function
0, // use default creation flags
&dwThreadId ); // returns the thread identifier

....
}

bool xxxxxx::ThreadFuntion ()
{

}

// Static function.
DWORD xxxxxx::ThreadProc ( LPVOID pParam )
{
xxxxxx * pThis = reinterpret_cast<xxxxxx *="">( pParam );

if ( !pThis )
{
return -1;
}

// Call non static function.
if ( !pThis -> ThreadFuntion ())
{
return -1;
}

return 0;
}

Use CriticalSection (InitializeCriticalSection)to secure data Access.
Use Event (CreateEvent) with WaitForMultipleObjects or WaitForSingleObject for synchonysation.
Thinks to release handle ( THread, critical section, event...) when your finised.
Take care to thread and application ending condition.
Do not call GUI object (button, list, edit...) from the thread.

Bye...

...

Re: threadcreation

Mohanraj D11-Jun-08 2:30

Mohanraj D

11-Jun-08 2:30

i get the following error in the wincore if createthread is used,whast should be done???

ASSERT((p = pMap->LookupPermanent(m_hWnd)) != NULL ||
			(p = pMap->LookupTemporary(m_hWnd)) != NULL);
		}
		ASSERT((CWnd*)p == this);   // must be us

// Note: if either of the above asserts fire and you are
// writing a multithreaded application, it is likely that
// you have passed a C++ object from one thread to another
// and have used that object in a way that was not intended.
// (only simple inline wrapper functions should be used)
//
// In general, CWnd objects should be passed by HWND from
// one thread to another. The receiving thread can wrap
// the HWND with a CWnd object by using CWnd::FromHandle.
//
// It is dangerous to pass C++ objects from one thread to
// another, unless the objects are designed to be used in
// such a manner.
}
}

Raja

Re: threadcreation

achainard11-Jun-08 3:58

achainard

11-Jun-08 3:58

Check if your compilation option is in "multithread dll" mode

...

Re: threadcreation

Mohanraj D11-Jun-08 20:36

Mohanraj D

11-Jun-08 20:36

my application is set to this "Multi-threaded Debug (/MTd)",is that correct??

Raja

Re: threadcreation

achainard12-Jun-08 3:52

achainard

12-Jun-08 3:52

With MFC Application (exe) it's better to set it to "Multi-threaded Debug Dll", i known that it's not logique because it's an exe and not a dll but it's like that...

Smile | :)

...

OnTImer in CListCtrl [modified]

Anu_Bala11-Jun-08 1:02

Anu_Bala

11-Jun-08 1:02

Hi,

I have display the system timings in ListCtrl using OnTimer().
But when the scrollbar appearing in ListCtrl then the ListCtrl is getting shaked or vibrating liek that.
Whats the reason? My Ontimer coding is

CListCtrl *pCtrl = (CListCtrl*)GetDlgItem(IDC_REPLAYLIST);
char ListBoxStr[50];
CString now;
CTime time;
static int j=1;
int index = 0;

pCtrl->DeleteAllItems();
for(int i=0;i<=nosize;i++)>
{
sprintf(ListBoxStr,"%d",i+1);
pCtrl->InsertItem(i,(CString)ListBoxStr);
sprintf(ListBoxStr,"%s",rptime[i]);
pCtrl->SetItemText(i,1,(CString)ListBoxStr);
}

Initially nosize is zero.And then it incesed in thread function up to 100.

Anu

modified on Wednesday, June 11, 2008 7:15 AM

Re: OnTImer in CListCtrl

Jijo.Raj11-Jun-08 1:22

Jijo.Raj

11-Jun-08 1:22

You mean flicker in listCtrl while updating bulk amount of data? if thats the problem, then call LockWindowUpdate() before starting updating and after updating call UnlockWindowUpdate() to avoide the flicker. Refer here for more details - http://weseetips.com/2008/04/19/how-to-update-bulk-amount-of-data-to-gui-controls-without-flicker/[^]

Or your problem is something different?

Regards,
Jijo.

_____________________________________________________

http://weseetips.com[^] Visual C++ tips and tricks. Updated daily.

Re: OnTImer in CListCtrl

Anu_Bala11-Jun-08 1:48

Anu_Bala

11-Jun-08 1:48

Yes, thanks but Now window or View behind the dialog box is get flickering..not ListCtrl by using LockWindowUpdate()

Anu

Re: OnTImer in CListCtrl

Jijo.Raj11-Jun-08 2:04

Jijo.Raj

11-Jun-08 2:04

Check the OnTimer() for unwanted InvalidateRect() or function like that which generates WM_PAINT message. That can be the reason for your dialog flicker.

Regards,
Jijo.

_____________________________________________________

http://weseetips.com[^] Visual C++ tips and tricks. Updated daily.

snapshot code

projectip11-Jun-08 0:08

projectip

11-Jun-08 0:08

Any sample code in vc++ to take a snapshot of video stream played in a vlc control or any useful link in codeproject for the same?

Re: snapshot code

Hamid_RT11-Jun-08 1:16

Hamid_RT

11-Jun-08 1:16

See here[^] but im not sure its helpfuls for you or no?

Capture control

capint11-Jun-08 0:05

capint

11-Jun-08 0:05

I write a program to capture window controls. I used global mouse hook to catch mouse message.
I want that when I move my mouse to a control, there's a rectangle around that control. I got the handle of the control, drew the rectangle but my problem is when I move to another control, the previous rectangle hasn't disappeared yet. I tried RedrawWindow() like this but there was no effect :

CDC *hScrDC;
hScrDC = CDC::FromHandle ( ::GetDCEx(NULL, NULL, 0));
//Tmp is the CDC * of the control
Tmp->RedrawWindow(NULL, NULL, RDW_ERASE | RDW_INVALIDATE | RDW_FRAME | RDW_ALLCHILDREN);
RECT rect;
Tmp->GetWindowRect(&rect);
   int nX = rect.left;     
   int nY = rect.top;     
   int nX2 = rect.right;     
   int nY2 = rect.bottom;    
hScrDC->Rectangle(nX, nY, nX2, nY2);

Some one plz help me Rose | [Rose]

Re: Capture control

achainard11-Jun-08 2:12

achainard

11-Jun-08 2:12

If you draw the border around the button, you draw on his parent so try to made an InvalidateRect on his parent, thinks to increst the rect from the border width and use ClientToScreen ScreenToClient to adjust position of rect on parent.

Bye...

...

Re: Capture control

Nibu babu thomas11-Jun-08 2:14

Nibu babu thomas

11-Jun-08 2:14

capint wrote:
RDW_ERASE | RDW_INVALIDATE | RDW_FRAME | RDW_ALLCHILDREN);

Try combining these two flags RDW_ERASENOW, RDW_UPDATENOW along with above ones.

Nibu thomas
Microsoft MVP for VC++

Code must be written to be read, not by the compiler, but by another human being.

Programming Blog: http://nibuthomas.wordpress.com

Re: Capture control

capint11-Jun-08 3:02

capint

11-Jun-08 3:02

Thanks so much Nibu babu thomas, I got it Big Grin | :-D

Re: Capture control

Nibu babu thomas11-Jun-08 3:05

Nibu babu thomas

11-Jun-08 3:05

capint wrote:
Thanks so much Nibu babu thomas, I got it

Welcome!

FYI

Reason for above behavior...

From MSDN: The system sends this message when there are no other messages in the application's message queue.

So we here just forced a paint by adding those flags! Another way to do this will be to first call Invalidate() and then call UpdateWindow() which is similar to what we did!

Nibu thomas
Microsoft MVP for VC++

Code must be written to be read, not by the compiler, but by another human being.

Programming Blog: http://nibuthomas.wordpress.com

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