C / C++ / MFC

Re: confused in static member function of class.

8-Mar-16 21:37

Member functions need qualifiers in order for the compiler to know which function your code refers to. In the case of a static function the qualifer must be the class name, since static functions belong to the class: hence Class::Function(). For member functions the qualifer must be the instance reference, as non-static functions are attached to individual objects: hence object.Function() or objectpointer->Function().

Member 872694014-Mar-16 19:19

Member 8726940

14-Mar-16 19:19

thank you so much for clearing my doubt

Assertion failure While Editing CTreeView Label.

shanmugarajaa8-Mar-16 9:04

shanmugarajaa

8-Mar-16 9:04

Dear Friend,

After adding all necessary message handler to support to edit label in CTreeView

void CMyTreeView::OnBeginLabelEdit( NMHDR* /*pNMHDR*/, LRESULT* pResult)
{
	// This is the Limit the size of the Tag Name to 127
	CTreeCtrl &ctlFiles = GetTreeCtrl();
	ctlFiles.GetEditControl()->LimitText( 127 );
	*pResult = 0;
}

void CMyTreeView::OnEndLabelEdit( NMHDR * pNMHDR, LRESULT *  pResult )
{
	*pResult = TRUE;
}

BOOL CMyTreeView::PreTranslateMessage(MSG* pMsg)
{

	if ( pMsg->message == WM_KEYDOWN )
	{
		CTreeCtrl &ctlFiles = GetTreeCtrl();
		CEdit* edit = ctlFiles.GetEditControl();
		if (edit)
		{
			if( GetKeyState( VK_CONTROL ) && pMsg->wParam == VK_C )
			{
				edit->Copy();
				return TRUE;
			}
			if( GetKeyState( VK_CONTROL ) && pMsg->wParam == VK_V )
			{
				edit->Paste();
				return TRUE;
			}
			if( GetKeyState( VK_CONTROL ) && pMsg->wParam == VK_X )
			{
				edit->Cut();
				return TRUE;
			}
			if( GetKeyState( VK_CONTROL ) && pMsg->wParam == VK_Z )
			{
				edit->Undo();
				return TRUE;
			}
			if( pMsg->wParam == VK_RETURN || pMsg->wParam == VK_ESCAPE || pMsg->wParam == VK_CONTROL || pMsg->wParam == VK_INSERT )
			{
				edit->SendMessage(WM_KEYDOWN, pMsg->wParam, pMsg->lParam);
				return TRUE;
			}
		}
	}
	return CTreeView::PreTranslateMessage(pMsg);
}

If I press a character 'a' to 'z' and 'A' to 'z' then MFC throwing Assertion.

I don't know what I am missing out to avoid this issue.
Kindly help me on this.

Thanks,
S Shanmuga Raja

Re: Assertion failure While Editing CTreeView Label.

jeron18-Mar-16 9:43

jeron1

8-Mar-16 9:43

Which line does it occur on when you step through it, and what is the assertion being hit?

"the debugger doesn't tell me anything because this code compiles just fine" - random QA comment
"Facebook is where you tell lies to your friends. Twitter is where you tell the truth to strangers." - chriselst
"I don't drink any more... then again, I don't drink any less." - Mike Mullikins uncle

Re: Assertion failure While Editing CTreeView Label.

David Crow8-Mar-16 16:41

David Crow

8-Mar-16 16:41

shanmugarajaa wrote:
...MFC throwing Assertion.

Exactly what assertion is being thrown?

shanmugarajaa wrote:
Kindly help me on this.

Have you stepped through the code using the debugger?

"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

"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles

Re: Assertion failure While Editing CTreeView Label.

_Flaviu8-Mar-16 20:37

_Flaviu

8-Mar-16 20:37

You should avoid overriding PreTranslateMessage ... in your case, you can solve more elegant your task overriding WM_CUT[^], WM_COPY[^], and WM_PASTE[^].

Application crashes on calling OnPaint() function!?

Kiran Satish7-Mar-16 16:51

Kiran Satish

7-Mar-16 16:51

I have a dialog based MFC application that I am rewriting in VS2010 from its original VC++ 6.0 source. Everything works fine in VC++ 6.0

The main dialog contains many child dialogs (not pop-ups) in which one child dialog is used to draw a plot based on the values sent from main dialog. The main dialog calls a function (Draw_Points) within the child dialog and the child dialog draws it and it does as long as the plot hits the edge and then it calls OnPaint message to refresh the dialog so that it can start afresh from left.

C++

void CPlotDlg::Draw_Points(double value1, double value2)
{
	if(m_LastPoint1.x < (m_time_rect.right-2))
	{
		// Store the data for later retrieval	
		m_CurrentPoint1.x = m_LastPoint1.x + 1;
		m_CurrentPoint2.x = m_LastPoint2.x + 1;
// Do some calculations
		m_Data1[m_DataCounter] = value1;
		m_Data2[m_DataCounter++] = value2;
		CWnd *Ctrl = GetDlgItem(IDE_PLOTS);
		CDC *cdc = Ctrl->GetDC();
		HGDIOBJ original = NULL;
		original = cdc->SelectObject(GetStockObject(DC_PEN));
		cdc->SelectObject(pen1);
		cdc->MoveTo(m_LastPoint1);
		cdc->LineTo(m_CurrentPoint1);
		cdc->SelectObject(pen2);
		cdc->MoveTo(m_LastPoint2);
		cdc->LineTo(m_CurrentPoint2);	
		cdc->SelectObject(original);
		Ctrl->ReleaseDC(cdc);
		m_LastPoint1 = m_CurrentPoint1;
		m_LastPoint2 = m_CurrentPoint2;
	}
	else
	{
		OnPaint();
		Reset_PlotData();			
	}
}

void CPlotDlg::OnPaint()
{
	CPaintDC dc(this); // device context for painting
	// TODO: Add your message handler code here
	if(m_BUpdate)
	{
		CDialogEx::OnPaint();
		CWnd *Ctrl = GetDlgItem(IDE_PLOTS);
		Ctrl->InvalidateRect(NULL,true);
		Ctrl->UpdateWindow();
	}
	// Do not call CDialogEx::OnPaint() for painting messages
}

It crashes when the Draw_points function calls OnPaint function in its else section, and when OnPaint() function executes CPaintDC dc(this);

Any suggestions?

thanks

PKNT

Re: Application crashes on calling OnPaint() function!?

Richard MacCutchan7-Mar-16 21:59

Re: Application crashes on calling OnPaint() function!?

7-Mar-16 21:59

Kiran Satish wrote:
and then it calls OnPaint

Which you should never do; see WM_PAINT message (Windows)[^].

Kiran Satish8-Mar-16 3:40

Kiran Satish

8-Mar-16 3:40

Thanks for your reply Richard. Could you suggest a better way to refresh my child dialog edit control where I draw these lines?

PKNT

Re: Application crashes on calling OnPaint() function!?

Richard MacCutchan8-Mar-16 5:53

Re: Application crashes on calling OnPaint() function!?

8-Mar-16 5:53

Well, you need to rethink your design. You should collect all the information related to the drawing as a result of user interaction, file processing etc. You then call InvalidateRect to tell Windows that your data has changed, and your window/client needs to be repainted. Then in the control you call your paint function in response to receiving a WM_PAINT message. It is at that point that you draw your lines, shapes, text etc.

David Crow8-Mar-16 3:40

David Crow

8-Mar-16 3:40

Kiran Satish wrote:
OnPaint();

I'm thinking you should call Invalidate() instead of calling OnPaint() directly.

Re: Application crashes on calling OnPaint() function!?

Kiran Satish8-Mar-16 4:31

Kiran Satish

8-Mar-16 4:31

Yes, that did the trick. I do that in couple of other child dialogs, but was not using it in this dialog. Well, looks like you overlook something that's fundamental.

thanks David

PKNT

how execute query in access database with CRecordset file?

Le@rner4-Mar-16 18:05

Le@rner

4-Mar-16 18:05

hi all,

i m using Access database with ODBC connection in my application.

here i am generate a CRecordset derived Class for each table in Database.

now here i fetch record here using while loop with movenext.

this is slow in process.

i want to use Query here to fast my process.

please help anyone to execute query to fetch,insert or update record record in table.

thanks in advance.

Re: how execute query in access database with CRecordset file?

Victor Nijegorodov5-Mar-16 4:51

Victor Nijegorodov

5-Mar-16 4:51

Well, the first step is to create a query ( the easiest way would be to create it and test in the MS Access).
The second step - create the recordset that supports update and insert operations. See MSDN article [^] for details.

Re: how execute query in access database with CRecordset file?

David Crow5-Mar-16 16:55

David Crow

5-Mar-16 16:55

Le@rner wrote:

this is slow in process.

How are you measuring this?

Le@rner wrote:

please help anyone to execute query to fetch,insert or update record record in table.

Did you bother to read the docs? They'll answer most, if not all, of your questions. I have an article here that shows how to create a read-only recordset.

Other articles here.

AT command serially via C code

Member 123621671-Mar-16 6:57

Member 12362167

1-Mar-16 6:57

how to send at commands over serially via comport using C compiler and what will be the code

Re: AT command serially via C code

Jochen Arndt1-Mar-16 7:48

Jochen Arndt

1-Mar-16 7:48

Windows: Serial Communications[^]

Linux: http://www.tldp.org/HOWTO/Serial-Programming-HOWTO/[^] and Serial HOWTO[^]

Micro controllers: See the UART section in the data sheet and check if the manufacturer provides an application note about serial communication.

Passing macro parameters via function

Vaclav_1-Mar-16 4:48

1-Mar-16 4:48

<pre lang="

I am stumped again.
I have this macro which expect the parameter registerSAM to be a symbol , for example PIO_ODSR.
I like to pass such symbol to a function and just have no idea how to convert char* to such symbol.

The compiler is not much of a help, just flags an error.

This is how the macro is used now

P_CB[iIndex] = portREGISTER(digitalPinToPort(*TFT_LCD_ControlPins), PIO_OWER);
B_CB[iIndex] = digitalPinToBitMask(*TFT_LCD_ControlPins);

Like to replace the second paramater "registerSAM" symbol with a variable.

Here is a part of the compiler output with me using incorrect way to place the char* as a paramater:

sketch\A.h: In member function 'int TFT_LCD::TFT_LCD_AccessRegister(byte, char*, boolean, boolean, char*)':
sketch\A.h:31683:75: error: expected unqualified-id before '&' token
P_CB[iIndex] = portREGISTER(digitalPinToPort(*TFT_LCD_ControlPins),&(cRegisterType)); // PIO_ODSR); // STATUS register PIO_ODSR
^
sketch\AAA_SAMRegisters.h:21:49: note: in definition of macro 'portREGISTER'
#define portREGISTER(port,registerSAM) (&(port->registerSAM))

Any help would be appreciated.

"></pre>

Richard Andrew x641-Mar-16 5:58

Richard Andrew x64

1-Mar-16 5:58

Vaclav_Sal wrote:
#define portREGISTER(port,registerSAM) (&;(port->registerSAM))

Since you already have a & character in the macro definition, why do you have one in the macro call?

Vaclav_Sal wrote:
P_CB[iIndex] = portREGISTER(digitalPinToPort(*TFT_LCD_ControlPins),&(cRegisterType));

The difficult we do right away...
...the impossible takes slightly longer.

Vaclav_1-Mar-16 6:08

1-Mar-16 6:08

This was just an attempt to solve the problem, passing "just" char did not work either.
I thin I found a workaround / hack to fix this, but still like to know how to pass the symbol as a variable.

Richard MacCutchan1-Mar-16 10:52

1-Mar-16 10:52

I do not see any macro here, and I really cannot understand what all the above is supposed to do. It would really help, as I have suggested many times, if you showed the actual code clearly, and within <pre> tags so it is readable.

Vaclav_2-Mar-16 4:09

2-Mar-16 4:09

#define portREGISTER(port,registerSAM) (&(port->registerSAM))

Richard MacCutchan2-Mar-16 5:06

2-Mar-16 5:06

I think your excessive use of the addressof operator (&) is confusing the compiler.

Vaclav_3-Mar-16 4:34