Re: passin a variable from another class - C / C++ / MFC Discussion Boards

Re: passin a variable from another class

Christian Graus31-Oct-04 9:05

31-Oct-04 9:05

Natural_Demon wrote:
AfxGetApp()->WriteProfileString("Settings", "Zonename", m_Zonename2);

I'm assuming that your application overrides WriteProfileString to take a CAddzonename pointer. AfxGetApp will return an instance of the base class, you need to cast it to the specialised class that contains this method. as it stands, it's trying to call the base class method, as that's all it can see.

I think. It's kind of hard to wade through all of that badly formated code.

Christian

I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer

Re: passin a variable from another class

Natural_Demon31-Oct-04 10:10

Natural_Demon

31-Oct-04 10:10

//CAddzonename* m_Zonename; <-- seems to be good, but how to use it??
if(m_Zonename)
{
AfxGetApp()->WriteProfileString("Settings", "Zonename", m_Zonename);
}

returns ...
j:\Visual Studio Projects\win32\firstw32mfc2\firstw32mfcDlg.cpp(224) : error C2065: 'm_Zonename' : undeclared identifier

BTW, i tried that before

Bad = knowing 2 much

Re: passin a variable from another class

Christian Graus31-Oct-04 10:14

Christian Graus

31-Oct-04 10:14

That's a whole different problem. m_Zonename does not exist in the class where you're trying to use it, obviously.

Christian

I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer

Re: passin a variable from another class

Natural_Demon31-Oct-04 10:16

Natural_Demon

31-Oct-04 10:16

how smart u are, i found that also out, but what do i need or can i do about it??

Bad = knowing 2 much

Re: passin a variable from another class

Christian Graus31-Oct-04 10:20

Christian Graus

31-Oct-04 10:20

Natural_Demon wrote:
how smart u are, i found that also out, but what do i need or can i do about it??

If you're going to be sarcastic, you can get stuffed.

If you don't know how to declare or scope a variable, I suggest buying and reading C++ for dummies before asking questions here.

Christian

I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer

Re: passin a variable from another class

Natural_Demon31-Oct-04 10:41

Natural_Demon

31-Oct-04 10:41

i'm not getting sarcastic, but dont tell me it's obivious.
i'm trying to find out how, i'm already reading stuf the whoile weekend andf i have read about creating a global variable, but when i copy(adapting the code afcourse) the code, visual doesn't accept it.
somehow.

Bad = knowing 2 much

Re: passin a variable from another class

Christian Graus31-Oct-04 10:51

Christian Graus

31-Oct-04 10:51

Global variables are bad design anyhow. However, in C++, to declare something as global ( that is, not within the scope of any class ), it will still only be visible in files where the file that declares it is included. I found the best way to do this is to declare stuff in stdafx.h. But a better option would be to declare it within the class that you're trying to get at with AfxGetApp(), although you still need to cast that, as I said before.

Christian

I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer

Re: passin a variable from another class

Natural_Demon31-Oct-04 11:03

Natural_Demon

31-Oct-04 11:03

i tried to cast like this...
CAddzonename* m_Zonename;
//CString m_Zonename2 = m_Zonename;

and it returns this ...
j:\Visual Studio Projects\win32\firstw32mfc2\firstw32mfcDlg.cpp(222) : error C2440: 'initializing' : cannot convert from 'CAddzonename *' to 'ATL::CStringT<basetype,stringtraits>'
with
[
BaseType=char,
StringTraits=StrTraitMFC<char>
]
if i do this ...

CString m_Zonename2;
CAddzonename* m_Zonename;
m_Zonename2 = m_Zonename;

j:\Visual Studio Projects\win32\firstw32mfc2\firstw32mfcDlg.cpp(222) : error C2679: binary '=' : no operator found which takes a right-hand operand of type 'CAddzonename *' (or there is no acceptable conversion)
...................................................................

CAddzonename* m_Zonename;
//m_Zonename2 = m_Zonename;

//if(m_Zonename)
//{
AfxGetApp()->WriteProfileString("Settings", "Zonename", m_Zonename);
}

this will return ...
j:\Visual Studio Projects\win32\firstw32mfc2\firstw32mfcDlg.cpp(226) : error C2664: 'CWinApp::WriteProfileStringA' : cannot convert parameter 3 from 'CAddzonename *' to 'LPCTSTR'

Bad = knowing 2 much

Re: passin a variable from another class

Christian Graus31-Oct-04 11:41

Christian Graus

31-Oct-04 11:41

Natural_Demon wrote:
CString m_Zonename2;
CAddzonename* m_Zonename;
m_Zonename2 = m_Zonename;

Duh. Why do you expect to convert a string from an instance of your class ?

Natural_Demon wrote:
this will return ...
j:\Visual Studio Projects\win32\firstw32mfc2\firstw32mfcDlg.cpp(226) : error C2664: 'CWinApp::WriteProfileStringA' : cannot convert parameter 3 from 'CAddzonename *' to 'LPCTSTR'

Bloody hell. Follow my advice, or stop asking me.

Christian

I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer

html dialog

Natural_Demon31-Oct-04 3:56

Natural_Demon

31-Oct-04 3:56

hello, i have made a dialog with HTML and my question how to prevent if u press enter that the app closes itself.

HRESULT Cmfc2htmlDlg::OnButtonOK(IHTMLElement* /*pElement*/)
{
OnOK();
return S_OK;
}

HRESULT Cmfc2htmlDlg::OnButtonCancel(IHTMLElement* /*pElement*/)
{
OnCancel();
return S_OK;
}

what do i need to do, so it doesn't close if u press the enter bottun on your keyboard.

kind regards,

marco

Re: html dialog

Michael Dunn31-Oct-04 8:55

Michael Dunn

31-Oct-04 8:55

See the FAQ:

7.4 How do I prevent a dialog from closing when the user presses Enter or Esc?[^]

--
I'm Michael Dunn and I approve this post.

Vote Trogdor in oh-four!

Re: html dialog

Natural_Demon31-Oct-04 9:00

Natural_Demon

31-Oct-04 9:00

thnx, normaly i find anything on google, but i was lazy and i tried somany things

thank u

kind regards,

marco

Bad = knowing 2 much

Re: html dialog

faroqtam31-Oct-04 10:44

faroqtam

31-Oct-04 10:44

you can do this with many ways as follows:-
1- Yourclass::OnOk()
{
// make it empty
}
2- use SetwindowHookEx function to capture Keyboard keys
and u can compare the wpararm parameter in your callback function if it =13 then Enter key has been pressed and you
can do any thing you need.

after this if broblem is found contact me on faroq_tam2004@yahoo
to send to you some source code

faroq from yemen thammar
working in thammar universty and my intersted about network and security
im programmer from 6 years ago and ihave my B.C from this universty

Re: html dialog

Christian Graus31-Oct-04 12:44

Christian Graus

31-Oct-04 12:44

faroqtam wrote:
use SetwindowHookEx function to capture Keyboard keys

You must be kidding.

Christian

I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer

_beginthreadex and WaitForSingleObject

Bob Stanneveld31-Oct-04 3:50

Bob Stanneveld

31-Oct-04 3:50

Hello,

I'm doing a multithreaded application that creates threads using the _beginthreadex api.

At some point I need to wait for the thread to exit (it exits normally) using the WaitForSingleObject api.

When I'm debugging , the thread function just exits normally. After the thread has exited, the <waitforsingleobject< code=""> api does not return, but still waits on the thread handle.

I'm not signalling the thread handle (which I don't think I should) and the thread has default access.

Is there anything that I should do with the thread handle before the thread exits?

Thanks in advance.

Multiply it by infinity and take it beyond eternity and you'll still have no idea about what I'm talking about.

Re: _beginthreadex and WaitForSingleObject

valikac31-Oct-04 6:41

valikac

31-Oct-04 6:41

One solution is an event.

Kuphryn

Re: _beginthreadex and WaitForSingleObject

Bob Stanneveld31-Oct-04 6:45

Bob Stanneveld

31-Oct-04 6:45

Yeah, but MSDN says that you can use the wait api's on thread handles created by _beginthreadex. Since that solution would be more elegant than using another event or synchronisation primitive, I prefer too use that solution...

Multiply it by infinity and take it beyond eternity and you'll still have no idea about what I'm talking about.

Re: _beginthreadex and WaitForSingleObject

valikac31-Oct-04 8:19

valikac

31-Oct-04 8:19

Correct. An independent event allows for reusability. Otherwise, call _endthreadex() before returning zero.

Kuphryn

Re: _beginthreadex and WaitForSingleObject

Michael Dunn31-Oct-04 8:59

Michael Dunn

31-Oct-04 8:59

It's hard to say without seeing your code, but the first thing to check is that you're waiting on the thread handle, not the thread ID. The handle is the return value from _beginthreadex() (you need to cast it to HANDLE) while the ID is returned via the last parameter of _beginthreadex().

--
I'm Michael Dunn and I approve this post.

Vote Trogdor in oh-four!

Re: _beginthreadex and WaitForSingleObject

Bob Stanneveld31-Oct-04 10:07

Bob Stanneveld

31-Oct-04 10:07

Hello,

I'm certain that I'm passing the handle returned by _beginthreadex to WaitForSingleObject.

I have to say a couple a things about the thread code:
1) It's a class
2) You can post messages to the thread function
3) The thread handle cannot be changed (it's not constant, but there is no statement that modifies the variable)
4) The thread functions returns after posting a TM_EXIT message

Anyhow, here's some code:
I create the thread like this:

<br />
m_hThread  = (HANDLE) _beginthreadex(NULL, 0, CThread::Run, this, 0, &m_nThreadID);<br />
<br />
	// was the thread created succesfully<br />
	if( m_hThread == 0 )<br />
	{<br />
		// error...<br />
	}<br />

The thread is terminated like this:

<br />
PostMessage(TM_EXIT);<br />
<br />
if( bWaitForTermination == TRUE)<br />
{<br />
	switch( ::WaitForSingleObject(m_hThread, INFINITE) )<br />
	{<br />
	case WAIT_FAILED:<br />
		{		<br />
			CStdString szError = "ERROR: Waiting for thread (0x%X, ThreadID: %d) termination failed. Reason:\n";<br />
			INTERNAL_LOCK();<br />
			szError.Format(szError, m_hThread, m_nThreadID);<br />
<br />
			GetLastErrorMessage(szError);<br />
<br />
			this->SetError(szError);<br />
<br />
			return TRC_UNKNOWNERROR;<br />
		}<br />
	case WAIT_TIMEOUT:<br />
		{<br />
			return TRC_WAITTIMEOUT;<br />
		}<br />
	} // switch( ::WaitForSingleObject(m_hThread, dwTimeOut) )<br />
} // if( bWaitForTermination == TRUE )<br />

Multiply it by infinity and take it beyond eternity and you'll still have no idea about what I'm talking about.

Solved!

Bob Stanneveld31-Oct-04 10:23

Bob Stanneveld

31-Oct-04 10:23

Thanks to the unit test, the problem was found. There was a litle bug in the CThread::PostMessage which caused that 1 message remains in the queue while the thread thinks it's empty...

Multiply it by infinity and take it beyond eternity and you'll still have no idea about what I'm talking about.

Eval Logical Expression

Mathias S.31-Oct-04 0:58

Mathias S.

31-Oct-04 0:58

I need to evaluate some logic expression at runtime in C++.
Stuff like "(a OR b) AND (NOT c OR d)"
( a,b,c,d is logical values of TRUE or FALSE. ( 0 or 1) )

I search google for hours and found a lot. But nothing really useful.
Anybody got any classes , code samples , links or anything that can help me out ?

/ Mathias S.

BitBlt not working for printer

Anorexic Tribble31-Oct-04 0:29

Anorexic Tribble

31-Oct-04 0:29

I have a piece of code that implements a transparent bitmap by taking a copy of a rectangle in the dc, manipulating it and then copying it back again. Everything works fine for display DCs and even print preview. However it all goes wrong when I use a printer DC. The copying from the printer DC to a memory DC just doesn't happen. The result from BitBlt is TRUE, indicating success, but it actually does nothing. A test picture that is inserted beforehand remains intact. Perhaps it is a problem with the printer driver (Epson CX3200). GetDeviceCaps says that it implements BitBlt.

Has anyone else had a similar problem or knows of a solution?

Re: BitBlt not working for printer

faroqtam31-Oct-04 10:14

faroqtam

31-Oct-04 10:14

try with anthor bliting functions as Dibdraw or anthor.

faroq from yemen thammar
working in thammar universty and my intersted about network and security
im programmer from 6 years ago and ihave my B.C from this universty

Re: BitBlt not working for printer

Roger Allen1-Nov-04 3:06

Roger Allen

1-Nov-04 3:06

See my article "Printing tips and tricks from the trenches" in the printing section. It covers this and over topics.

If you vote me down, my score will only get lower

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