Re: A Thready Question - C / C++ / MFC Discussion Boards

Xavier Shay1-Nov-01 17:03

1-Nov-01 17:03

I've been recently experimenting with threads and found that I got an error when i tried to pass a class member function as the Thread entry point (something about not converting void(void *) to void(__cdcl)(void *). I tried attaching the __cdcl (somethin like __cdcl anyway) to the function definition but it did not help. Is this possible and if not is there a way to have global functions access member variables (friend keyword??)?

- X

Re: A Thready Question

Nish Nishant1-Nov-01 17:09

Nish Nishant

1-Nov-01 17:09

You cannot pass non-static functions as the thread proc.
But what you can do is to pass a pointer to your class's instance as the LPVOID parameter
Then you can cast the pointer to your class and use the members from the global function.

Nish

Re: A Thready Question

Xavier Shay1-Nov-01 17:23

Xavier Shay

1-Nov-01 17:23

Thankyou greatly. A reply in 6 minutes. Who would have thought??

- X

Re: A Thready Question

Nish Nishant1-Nov-01 17:35

Nish Nishant

1-Nov-01 17:35

That's Code Project for you

Smile | :)

Nish

Re: A Thready Question

Michael Dunn1-Nov-01 17:43

Michael Dunn

1-Nov-01 17:43

See the VC forum FAQ. Smile | :)

--Mike--
http://home.inreach.com/mdunn/
If there's something strange / in your VC code / Who you gonna call? / Ghostbusters!
Heart | [heart]

your

with

and

Re: A Thready Question

Deepak Khajuria1-Nov-01 20:44

Deepak Khajuria

1-Nov-01 20:44

You can make the function as Static member of the class(instead of global class) and then pass it to thread function.

Deepak Khajuria

Re: A Thready Question

Nish Nishant1-Nov-01 20:48

Nish Nishant

1-Nov-01 20:48

But then he wont be able to access the non-static members

Nish

Re: A Thready Question

Deepak Khajuria1-Nov-01 21:02

Deepak Khajuria

1-Nov-01 21:02

Yes, he has to pass the instance of the class as parameter,or something similar.

But the main difference is that the static function of the class has full access to the class, where as global function cannot access the protected/private members.

Deepak Khajuria

Re: A Thready Question

Nish Nishant1-Nov-01 21:10

Nish Nishant

1-Nov-01 21:10

He can always call the static functions of his class from his global function anyway. Thus he can also access all static members (via the static function, of course)

Nish

Re: A Thready Question

Deepak Khajuria1-Nov-01 22:42

Deepak Khajuria

1-Nov-01 22:42

The static functions & global functions are same in sense that you do have instance of the class(this) in it. You need to get instance of the class from somewhere to call its non-static members.

But the main difference is that the static function of the class has access to the protected/private members of the object of same class.

This does not hold true for the global functions.(unless you make them friend)

So in a thread where you require direct access to class protected/private members, it is better to make thread function as static member of the class.

Deepak Khajuria

the format of MIME?

cococut1-Nov-01 14:57

cococut

1-Nov-01 14:57

the MIME file of eml looks like this:

From: "Doug Sauder" <doug@example.com>
To: "Joe Blow" <jblow@example.com>
Subject: Test message from Microsoft Outlook 00
Date: Wed, 17 May 2000 19:42:10 -0400
Message-ID: <ndbbiakopkhfgplcodiggekfchaa.doug@example.com>
MIME-Version: 1.0
Content-Type: multipart/mixed;
boundary="----=_NextPart_000_0008_01BFC037.FDD8EE90"
X-Priority: 3 (Normal)
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0)
Importance: Normal
X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2314.1300

This is a multi-part message in MIME format.

------=_NextPart_000_0008_01BFC037.FDD8EE90
Content-Type: multipart/alternative;
boundary="----=_NextPart_001_0009_01BFC037.FDD8EE90"

------=_NextPart_001_0009_01BFC037.FDD8EE90
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

All cows eat grass=20
=20

------=_NextPart_001_0009_01BFC037.FDD8EE90
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

All cows eat grass =

=20

------=_NextPart_001_0009_01BFC037.FDD8EE90--

------=_NextPart_000_0008_01BFC037.FDD8EE90
Content-Type: image/png;
name="greenball.png"
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
filename="greenball.png"
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------=_NextPart_000_0008_01BFC037.FDD8EE90
Content-Type: image/png;
name="redball.png"
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
filename="redball.png"
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------=_NextPart_000_0008_01BFC037.FDD8EE90--

the question is :
Can you tell why the line "boundary="----=_NextPart_000_0008_01BFC037.FDD8EE90"
" is required.

and ------=_NextPart_000_0008_01BFC037.FDD8EE90--
???
any suggestions?
thanks in advance!

Re: the format of MIME?

Nish Nishant1-Nov-01 16:15

Nish Nishant

1-Nov-01 16:15

To mark the beginning and end of each attachment

Nish

Re: the format of MIME?

markkuk1-Nov-01 21:13

markkuk

1-Nov-01 21:13

This is a MIME message that contains binary attachments in addition to plain text. The "boundary=" header defines the string that is used to separate the various parts of the message. The actual separator has "--" prefixed to it, and the final separator has also "--" at the end. All this is defined in RFC 2046. If you are writing an application that creates/receives MIME messages you must read the RFCs 2045 - 2049!

DirectShow Application "Release Version" Problem!!! help!!!!!!!!!

1-Nov-01 14:19

I have written a application, which use DirectShow
video playback system and DivX video codec to playback the mpeg-4 video.
In "debug" version, all is ok!

but after I compile and link as "Release version", when I test it, it go awry.

here is some code:

HRESULT CVideoWnd::PrePlayVideo()
{
JIF(CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC_SERVER,
IID_IGraphBuilder, (void **)&m_pGraph));

....
JIF(m_pGraph->QueryInterface(IID_IMediaControl, (void**)&m_pMediaControl));
JIF(m_pGraph->QueryInterface(IID_IMediaEventEx, (void **)&m_pMediaEvent));
JIF(m_pGraph->QueryInterface(IID_IMediaSeeking, (void **)&m_pMediaSeek));
JIF(m_pGraph->QueryInterface(IID_IVideoWindow, (void **)&m_pVideoWnd));

JIF(m_pGraph->QueryInterface(IID_IBasicVideo, (void **)&m_pBasicVideo));
JIF(m_pGraph->QueryInterface(IID_IBasicAudio, (void **)&m_pBasicAudio));

HWND hWnd = GetSafeHwnd();
ASSERT(hWnd != NULL);
JIF(m_pVideoWnd->put_Owner((OAHWND)hWnd));
JIF(m_pVideoWnd->put_WindowStyle(WS_CHILD | WS_CLIPSIBLINGS));

JIF(m_pMediaEvent->SetNotifyWindow((OAHWND)hWnd, WM_GRAPHNOTIFY, 0));
VERIFY(GetDuration(&m_llDuration));
JIF(InitVideoWindow(1, 1));

ShowWindow(SW_SHOWNORMAL);
UpdateWindow();
SetForegroundWindow();
SetFocus();
JIF(m_pVideoWnd->SetWindowForeground(0));
..
}

HRESULT CVideoWnd::OnVideoPlay()
{
ASSERT(m_pMediaControl);
HRESULT hr;

OAFilterState fs = State_Running;
hr = m_pMediaControl->Run();
if (hr == S_FALSE)
hr = m_pMediaControl->GetState(INFINITE, &fs);

m_psCurrent = Running;
m_nTimerID = SetTimer(1, 100, NULL);
return S_OK;
}

....
HRESULT CVideoWnd::OnGraphNotify()
{
LONG evCode, evParam1, evParam2;
HRESULT hr=S_OK;

while(SUCCEEDED(m_pMediaEvent->GetEvent(&evCode, &evParam1, &evParam2, 0)))
{
// Spin through the events
hr = m_pMediaEvent->FreeEventParams(evCode, evParam1, evParam2);

if(EC_COMPLETE == evCode)
{
LRESULT lRepeat = GetParent()->SendMessage(WM_QUERY_IS_REPEAT);
if (lRepeat == 0)
OnVideoStop();
else
{
LONGLONG pos = (LONGLONG)GetParent()->SendMessage(WM_QUERY_BEGIN_POS);
JIF(m_pMediaSeek->SetPositions(&pos, AM_SEEKING_AbsolutePositioning ,
NULL, AM_SEEKING_NoPositioning));
}
}
}

return hr;
}

so, I try as follow:

1. I set "Win32 Release" building mode, but I reserver "debug info" in application
and set debug info is for "Program Database for edit and continue"
I have found the bug is in the function OnGraphNotify()

when I play it, the points "m_pMediaEvent" in function OnGraphNotify become "0", in fact, such as
m_pMediaControl, m_pMediaEvent, m_pMediaSeek, m_pGraph, all become 0.

I have initialized all the pointers in function "PrePlayVideo()", and when I play
it, I have check all the pointers In "Release version" have been initialized.

but, when my video window receive the event of filter graph manager, the pointer became o;
why? who can help me???

2. When I modify project setting, I set "C++ - Code Generation - Use run-time library" is "Debug Multithreaded",
now, all is succeed. why?

once I set this is "Multithreaded" in "Release Version", it run failed.
but I change it to "debug multithreaded", it run succeed.

In "Debug Multithreaded", the pointer "m_pMediaControl", "m_pMediaEvent", "m_pMediaSeek", "m_pGraph", is ok;
but all became 0 in "Multithreaded".

who can tell me the reason?
thank you very much!

Please Help with Tooltips - Project Included

Craig Miller1-Nov-01 13:15

Craig Miller

1-Nov-01 13:15

Hi,

I have been trying for a couple of days to get some help with my tooltip problem and it doesn't seem that anyone can help me, so I created a sample project that displays the problem.

Please download the project at http://www.roninkuma.com/ToolTipTest.zip This application uses the Microsoft Date/Time picker ActiveX control, I figured everyone would have that one. If you run the project and put the mouse in the top left hand corner of the date/time control, you will see a tooltip pop up under the mouse that say's "Hello", after a second or two, you'll see another tooltip pop up at the bottom of the window that also say's "Hello".

Can anyone help me to get rid of the "Hello" at the bottom of the screen?

Thanks in advance for any help you can provide

Re: Please Help with Tooltips - Project Included

Kannan Kalyanaraman2-Nov-01 2:23

Kannan Kalyanaraman

2-Nov-01 2:23

Hi,

http://support.microsoft.com/support/kb/articles/q141/8/71.asp

says how to add tooltip control to an activeX control. Not sure if this is the problem. Hope this helps.

Cheers
Kannan

Re: Please Help with Tooltips - Project Included

Craig Miller2-Nov-01 5:38

Craig Miller

2-Nov-01 5:38

Hi Kannan,

Thanks for the suggestion but I don't think this will work for me. I don't have the source for the ActiveX control, my application is just the consumer of the control.

Thanks again for taking the time to look at this for me,

Craig

ifstream question

1-Nov-01 11:16

if you are using ifstream and ofstream, how can you ensure that when you use the getline method, you do not overrun your buffer size? (i.e. if you use basic C++ methods and classes, how do you make sure that your program can read a 1000 character line as well as 10 character line, without wasting memory by creating large arrays beforehand?

i.e. what's the best sol'n for this:

while(!fin->eof())
{
fin->getline(x, sizeof(x), '\n');
}

Re: ifstream question

markkuk1-Nov-01 21:18

markkuk

1-Nov-01 21:18

Use the non-member function istream& getline(istream& strm, string& str, char delim) instead to read the data into a std::string

Experienced proggers, help

ParaSwarm1-Nov-01 11:00

ParaSwarm

1-Nov-01 11:00

Hey, I'm programming Windows in API, I'm new at it, and I don't quite understand how to change the size of a font. I have this under my WM_PAINT procedure.
case WM_PAINT:
hdc = BeginPaint(hwnd, &ps);
GetClientRect (hwnd, &rect);
SetBkMode(hdc,TRANSPARENT);
SelectObject(hdc,GetStockObject(DEFAULT_GUI_FONT));
TextOut(hdc,5,5,"Need help..",25);
DeleteObject(SelectObject(hdc,GetStockObject(DEFAULT_GUI_FONT)));
EndPaint(hwnd, &ps);
return 0;
See the TextOut? How would I make it so it says "Need help..." in, like, 20 font instead of a 10 size font. Any help would be appreciated. Thanks =)

Re: Experienced proggers, help

Fazlul Kabir1-Nov-01 11:11

Fazlul Kabir

1-Nov-01 11:11

Use ::CreateFont(..) to create custom sized font.

HFONT hFont = ::CreateFont(..);
::SelectObject(hdc, hFont);

Hope this helps.

// Fazlul

Get RadVC today! Play RAD in VC++
http://www.capitolsoft.com

Re: Experienced proggers, help

Nish Nishant1-Nov-01 13:28

Nish Nishant

1-Nov-01 13:28

font1.CreateFont(20,0,0,0,FW_NORMAL,0,0,0,DEFAULT_CHARSET,
		OUT_CHARACTER_PRECIS,CLIP_CHARACTER_PRECIS,
		DEFAULT_QUALITY,DEFAULT_PITCH | FF_DONTCARE,"Arial");

SetFont(&font1,TRUE);

Re: Experienced proggers, help

Nish Nishant1-Nov-01 13:33

Nish Nishant

1-Nov-01 13:33

oops!

That's for MFC. And for controls too.
I didnt notice you were doing a non-MFC program.

you can use the SDK call CreateFont that returns an HFONT.
The parameters are same.

and send a WM_SETFONT message with this HFONT as the WPARAM

Nish

Re: Experienced proggers, help

Nish Nishant1-Nov-01 13:36

Nish Nishant

1-Nov-01 13:36

oops again!

as I said that's for controls.
for affecting your TextOut calls

use SelectObject(GetDC(hWnd),hFont)

Nish

Re: Experienced proggers, help

Fazlul Kabir1-Nov-01 13:47

Fazlul Kabir

1-Nov-01 13:47

I guess he is already in a WM_PAINT proc. and thus have a valid HDC handle. This should allow him to use

::SelectObject(hdc, hFont);

// Fazlul

Get RadVC today! Play RAD in VC++
http://www.capitolsoft.com

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