C / C++ / MFC Discussion Boards

How can I access a document member variable from a dialog window?

Darryl Bryk15-Jun-09 11:05

15-Jun-09 11:05

In a multi-doc. app. with the view based on CScollView which is used to display images, I'd like to display a dialog window with some histogram graphics in it. The problem is the OnPaint function for the dialog needs a few of the document's variables to draw the image's histogram. Making the variables pulic doesn't help because the compiler says they're non-static. And I can't seem to get the GetDocument() function to work in the dialog class like it does for the View class. Is there a way to do this with GetDocument() or do I have to derive the dialog class to the View some how, or a ChildView? Any help would be appreciated.

Re: How can I access a document member variable from a dialog window?

Stuart Dootson15-Jun-09 14:53

Stuart Dootson

15-Jun-09 14:53

Pass references or pointers to the variables into the dialog, either through a constructor or through accessors.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: How can I access a document member variable from a dialog window?

Darryl Bryk17-Jun-09 13:41

Darryl Bryk

17-Jun-09 13:41

Aha! I think that will work. Thanks!

Static function variable problem

alikalik15-Jun-09 8:18

alikalik

15-Jun-09 8:18

Hello,
I have a function that is called from a dll and contains static variable:

void myFn(double data)
{
	static double x;
	...
}

At each iteration x increases on some value.
The problem occurs when pass diffent data at the same time (i.e. call the function more than once at the same time), x variable mixes all values.

data1[] = 1,2,3
data2[] = 4,5,6

The result for the first call must be 1+2+3 = 6
The result for the second call must be 4+5+6 = 15

But now the result for the first call will be 1+4+2+5+... and so on.

How to avoid this problem?

Re: Static function variable problem

David Crow15-Jun-09 10:03

David Crow

15-Jun-09 10:03

At first glance, your problem sounds like one of synchronization. But then I could not figure out how you were calling myFn(). It is expecting a single argument, yet you've shown two arrays. Are you passing one member of the array with each call to myFn()?

alikalik wrote:
The result for the first call must be 1+2+3 = 6
The result for the second call must be 4+5+6 = 15

But now the result for the first call will be 1+4+2+5+... and so on.

Nothing you've shown supports this. Confused | :confused:

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Re: Static function variable problem

C^hris L^osinger15-Jun-09 10:04

C^hris L^osinger

15-Jun-09 10:04

alikalik wrote:
call the function more than once at the same time

are you calling the DLL from multiple threads ?

image processing toolkits | batch image processing

Re: Static function variable problem

alikalik15-Jun-09 18:43

alikalik

15-Jun-09 18:43

I'm creating add-in for MS Excel.
The argument is a value in a cell.

So for instance, if I call MyFn(B11) and MyFn(B12), where B11 and B12 are cells, the result will be wrong.

Re: Static function variable problem

led mike15-Jun-09 10:27

led mike

15-Jun-09 10:27

Try putting that code in your main() function.

Re: Static function variable problem

CPallini15-Jun-09 10:41

CPallini

15-Jun-09 10:41

Remove the static local variable making it an argument passed by reference.
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return value of a fun() [modified]

Anand966915-Jun-09 7:21

Anand9669

15-Jun-09 7:21

Hi..

return i + i;

Please let me know what does this return?

wether it reurns addition of i + i Or it returns only i.
Thanks.....

modified on Monday, June 15, 2009 1:40 PM

Re: return value of a fun()

David Crow15-Jun-09 7:40

David Crow

15-Jun-09 7:40

Why not just try it and see?

Anand9669 wrote:
wether it reurns addition of i + i Or it returns only i.

Statements end with semicolons, so 2i will be returned. Otherwise, why would the compiler choose to ignore the + i; (and thus produce an error)?

Re: return value of a fun()

Anand966915-Jun-09 7:43

Anand9669

15-Jun-09 7:43

Thanks for ur reply
right now i don't have c compiler in my machine..

Re: return value of a fun()

Luc Pattyn15-Jun-09 8:41

Luc Pattyn

15-Jun-09 8:41

it would be very much the same in the majority of programming languages...

Assuming i is int,

int a=i+i;
return a;

does return the same value as

return i+i;

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DISCLAIMER: this message may have been modified by others; it may no longer reflect what I intended, and may contain bad advice; use at your own risk and with extreme care.

Re: return value of a fun()

Anand966915-Jun-09 20:10

Anand9669

15-Jun-09 20:10

Thanks for ur reply..

u mean to say it is as good as

return (i + i);

and there is no need of paranthesis...

PropertyPage - OnQueryCancel

JBAK_CP15-Jun-09 7:06

JBAK_CP

15-Jun-09 7:06

I am trying to handle the 'Cancel' button in my property pages (wizard) and I've implemented the 'OnQueryCancel' function to catch the cancel message successfully, but unfortunately it seems that the 'OnQueryCancel' function is being called twice if the user clicked the cancel button. Any ideas on how I could address this issue? Thanks!

virtual BOOL OnQueryCancel();


BOOL CWiz_Page1::OnQueryCancel()
{	
	int ret;
	ret = MessageBox("Are you sure?", NULL, MB_YESNO);
	
	if(ret == IDYES)
		return true;
	else
		return false;
}

Re: PropertyPage - OnQueryCancel

David Crow15-Jun-09 7:54

David Crow

15-Jun-09 7:54

JBAK_CP wrote:
...but unfortunately it seems that the 'OnQueryCancel' function is being called twice if the user clicked the cancel button.

By default, this does not happen. You've added (or removed) something that is causing this. Trying creating a new CPropertySheet-based project from scratch and note its behavior.

CreateImageEx problem with CListCtrl drag and drop

bhanu_850915-Jun-09 5:39

bhanu_8509

15-Jun-09 5:39

Dear All,

I have problem with the CListCtrl drag and drop. I used the CreateImageEx to display the image while dragging the contents of the CListCtrl but unfortunately the image is displaying at the left top corner of the screen and not relevant to my GUI where the CListCtrl is placed.

The following is the code snippet. Please advice why the image is displayed like that.

//call to the dragging method
void TestDlg::OnLvnBeginrdragList3(NMHDR *pNMHDR, LRESULT *pResult)
{
	LPNMLISTVIEW pNMLV = reinterpret_cast<LPNMLISTVIEW>(pNMHDR);
	OnBegindrag(&pList, pNMHDR);
	*pResult = 0;
}

//Dragging method
void TestDlg::OnBegindrag(CListCtrl* pList, NMHDR* pNMHDR) 
{
	NM_LISTVIEW* pNMListView = (NM_LISTVIEW*)pNMHDR;
	if (pList->GetSelectedCount() <= 0)
		return;  // No row selected
	int iItem = pList->GetSelectedCount();
	POINT pt;
	m_pDragImage = CreateDragImageEx(pList, &pt);
		if (m_imageList == NULL)
		return;
	m_pDragWnd = pList;
	CPoint ptStart = pNMListView->ptAction;
	ptStart -= pt;
	m_pDragImage->BeginDrag(0, ptStart);
	m_pDragImage->DragEnter(GetDesktopWindow(), pNMListView->ptAction);
	SetCapture();
}

Re: CreateImageEx problem with CListCtrl drag and drop

bhanu_850915-Jun-09 23:39

bhanu_8509

15-Jun-09 23:39

Please anybody help me!!!

Calling the functions from different class

aravind.sn15-Jun-09 2:55

aravind.sn

15-Jun-09 2:55

Hello all, im very much confused with this make this snippet work,, let me explain my problem in simple. please follow the folling code.
class ClassA
{
public:
function_A();
function_B();
}

class Class1
{
public:
ClassA A1
Function_1();
}

class Class1::Function_1()
{
Dlg1.DoModal();

A1.function_A();
A1.function_B();
}

class ClassDlg
{
FunDlg();
}

ClassDlg::OnRefresh()
{
i wanted "A1.function_A();"
i wanted "A1.function_B();"
}

The Dialog window will be called by "Class1::Function_1()" so after closing the dialog window the function "A1.function_A();" and "A1.function_B();" are called in order to update the contents of the mainpage(say property page). actually the contents are modified in the dialog window. so what i wanted to do is call the functions "A1.function_A();" and "A1.function_B();" before closing the dialog window say at after pressing the"Refresh" button(OnRefresh will be called). Im confused its not just happening what i desired. can any expert give me a solution, like is there any try statement i can give..??
please help me...

Re: Calling the functions from different class

_AnsHUMAN_ 15-Jun-09 3:08

_AnsHUMAN_

15-Jun-09 3:08

From your question it seems that you want to call the function of classA from ClassDlg. Why don't you create the object for class A in ClassDlg as well as you do in Class1?
or please rephrase your question if I understood incorrectly.

You need to google first, if you have "It's urgent please" mentioned in your question.
Wink | ;-)

_AnShUmAn_

Re: Calling the functions from different class

aravind.sn15-Jun-09 3:30

aravind.sn

15-Jun-09 3:30

Hi anshuman, thanks for your reply,
Actually,A1(object of ClassA) is like a handle to the table in the mainpage(flex grid). if i create 2 bjects that will create 2 flex grids. Instead i just wanted to update the already created table contents by this object A1.
"Dlg1" is the object of class "ClassDlg" where
class ClassDlg
{
public:
FunDlg();
OnRefresh()
}

i just wanted to call these function say "A1.function_A(); and A1.function_B();" inside the member function of class ClassDlg.

Setattribute in MSXML

siva45515-Jun-09 2:35

siva455

15-Jun-09 2:35

Hi,
how can i set an attribute with value at a particular postion in an Xml node....(im using MSXML)

Re: Setattribute in MSXML

Stuart Dootson15-Jun-09 3:47

Stuart Dootson

15-Jun-09 3:47

pradeep455 wrote:
particular postion in an Xml node

Particular position within an XML node? What do you mean by that exactly? What I read that as is that you want to ensure a particular ordering of attributes within an element - which you can't do, because attributes form an unordered (or more correctly, I guess, an arbitrarily ordered) collection.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: Setattribute in MSXML

siva45515-Jun-09 6:32

siva455

15-Jun-09 6:32

i mean suppose i have an xml file..

<test a1="1" a2="2">
</test>

and i need to add a0="0" before a1...is it possible...

Re: Setattribute in MSXML

Cedric Moonen15-Jun-09 7:50

Cedric Moonen

15-Jun-09 7:50

Why would you do something like that ? As far as I know, the order of the attributes is not important in the xml format. So, why is it a need to have a0 before a1 ?

Cédric Moonen
Software developer

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