Using function from other class - C / C++ / MFC Discussion Boards

Ruscoff15-Dec-09 11:26

15-Dec-09 11:26

Hi all,
i've a question(hypothetical situation):
There are two class

class1 with a void funct_cl1()and other methods;

(class1 use observer paradigm, funct_cl1 will be called with high frequency)

class2 is a thread with some functions;

In class2 i initialized class1 pointer like this: class1* cls1 = new class1() and i use some method of its but never funct_cl1.

if i put in pause (p.e with a long sleep) the thread of class2, the funct_cl1 belong to cls1 can be anyway executed with observer paradigm or is it block?

Regards

Marco

Re: Asyncronus class and your method

Moak15-Dec-09 12:59

Moak

15-Dec-09 12:59

Hi Marco, I try an answer.

Yes you can call a method from another thread, any object can be accessed from other threads. The real question is if the called functionality will be multithreading safe. Maybe this isn't even an issue in your case and you just wondered about ownership: Sleep() will only stop execution of one thread, but not prevent memory access from other threads. For example if class 2 creates an object of class1, which then is only used/called from another thread context, you don't even have to worry about multithreading (as long as lifetime of "class2 object thread" is longer than "class1 object thread").

Hope it helps
/M

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Re: Asyncronus class and your method

Ruscoff16-Dec-09 2:59

Ruscoff

16-Dec-09 2:59

perfect!

thank you!

MFC ListControl flicker in win7

yctsai15-Dec-09 8:08

yctsai

15-Dec-09 8:08

My program contains a ListControl(common control ).

I use LVS_EX_DOUBLEBUFFER style in window XP, it works well,
but it has flicker problem in window Vista and window 7.

Anyone know why this happen?

Thanks for your help.

CIPAddressCtrl cannot create vc+= mfc

saarfu15-Dec-09 5:08

saarfu

15-Dec-09 5:08

HI all,
i am struggling to create CIPAddressCtrl . i cannot use drag and driop as i am not using Cdialog, i have craeted a window using CFrameWindow.
have any one done this successfully.
here i could just see a edit control kind of thing when i create
CIPAddressCtrl IpAddr;
IpAddr.Create(.....);
dont know whats wrong.
any help will be gret for me..
Thanks

Re: CIPAddressCtrl cannot create vc+= mfc

Abhi Lahare15-Dec-09 13:04

Abhi Lahare

15-Dec-09 13:04

Try this.

1)Please check the return value from IpAddr.Create(.....); function.
2)Make sure that CIPAddressCtrl IpAdd is not a local variable to a function. This will destroy object after function call.

HTH
Abhi

VS2008 CMFCToolbar and inserting a combo box

Jerry Evans15-Dec-09 4:29

Jerry Evans

15-Dec-09 4:29

The VS2008 toolbar stuff is driving me nuts. The SetButtonInfo() call now seems to take an image index as 4th parameter rather than a width. I can create an embedded combobox if the button is set to TBBS_SEPARATOR but the combo overpaints the drop-arrow used to customise the toolbar. Anyone got an example that works?

Thx++

Jerry

Using function from other class

blackbolek15-Dec-09 2:41

blackbolek

15-Dec-09 2:41

Hi,

I've got an application with 3 dialogs: Monitor, UnitView, GroupStart. Each dialog has it's class named accordingly. Monitor is a main dialog which opens at the start of application. By clicking button on Monitor dialog you can open UnitView dialog. It is done like that:

<br />
        unitviewdialog[selection] = new CUnitView();<br />
	unitviewdialog[selection]->SetParent(this);<br />
<br />
	unis[selection] = new CDlgModalToModeless();<br />
	unis[selection]->DoDialog(unitviewdialog[selection]);<br />

Then on UnitView dialog you can click on next button to open GroupStart dialog:

<br />
                CGroupStart* dlg = new CGroupStart(this);<br />
		<br />
		dlg->DoModal();<br />
		delete dlg;<br />

There is a function SendMsg() which is public member of CMonitorDlg class, and which I need to use. I mean I have to call it from function which is public member of CGroupStart class.
Here is first few lines of this function:

<br />
BOOL CMonitorDlg::SendMsg(int destination, char *typec, char *content)<br />
{<br />
<br />
	int sum = 0;		<br />
<br />
  	coutbuff[0] = STX;  <br />
	coutbuff[1] = '0';<br />
	coutbuff[2] = '0';<br />

coutbuff is declared as char[410] and is public member of CMonitorDlg class.

Now - I'm calling this function from CGroupStart like that:

<br />
void CGroupStart::OnGstart() <br />
{<br />
char grpcmd[5];<br />
<br />
	if (groupid<0 || groupid>20)<br />
		return;<br />
<br />
	sprintf (grpcmd,"%d;1",groupid);<br />
	<br />
	((CMonitorDlg*)m_pWnd)->SendMsg(unit, "MO", grpcmd);<br />
<br />

The application crashes at this moment with Access Violation error.
I tried to run it under debugger, step by step and it took me to second line of SendMsg() function where it tries to assign STX to coutbuff[0]. So it looks like it cannot access coutbuff.
What am I doing wrong?
I'm using VC++ 6.0.

Re: Using function from other class

David Crow15-Dec-09 2:53

David Crow

15-Dec-09 2:53

blackbolek wrote:
((CMonitorDlg*)m_pWnd)->SendMsg(unit, "MO", grpcmd);

The application crashes at this moment with Access Violation error.

Are you sure that m_pWnd is a CMonitorDlg?

"One man's wage rise is another man's price increase." - Harold Wilson

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Re: Using function from other class [modified]

blackbolek15-Dec-09 4:16

blackbolek

15-Dec-09 4:16

Here is my declaration of m_pWnd for GroupStart class:

<br />
private:<br />
	CDialog* m_pWnd;<br />

When I change it for:

<br />
private:<br />
       CMonitorDlg* m_pWnd;<br />

it's still the same error in the same place. So it doesn't change anything.

m_pWnd is not 'initialized' anywhere. How should I initialize it?

modified on Tuesday, December 15, 2009 10:37 AM

Re: Using function from other class

Cedric Moonen15-Dec-09 4:26

Cedric Moonen

15-Dec-09 4:26

blackbolek wrote:
It's not 'initialized' anywhere. How should I initialize it?

I think you should really learn a bit more about the concept of classes in C++. This is really basic C++ stuff.
You have to pass an instance of your dialog to the GroupStart class (but instead of the generic CDialog, use a pointer to a CMonitorDlg instead, this way you won't need to cast). This is typically done in the constructor: you add an additional parameter in the constructor of GroupStart (and when you conctruct it from CMonitorDlg, you simply pass the this pointer).

Cédric Moonen
Software developer

Charting control [v2.0]
OpenGL game tutorial in C++

Re: Using function from other class

blackbolek15-Dec-09 4:50

blackbolek

15-Dec-09 4:50

Yes - that sorted the problem.

Thank you very much for your help.

Re: Using function from other class

Cedric Moonen15-Dec-09 3:21

Cedric Moonen

15-Dec-09 3:21

In addition to Devaid's answer, how did you initialize m_pWnd ? Are you sure it is not null ?

Cédric Moonen
Software developer

Charting control [v2.0]
OpenGL game tutorial in C++

Sorting In A Virtual ListControl

jannathali15-Dec-09 1:13

jannathali

15-Dec-09 1:13

I am Having a Virtual List Control,with 5 columns.if i double clock on the first column i want to sort the list by that column,& if i clicked on second column i want to sort it by that column & till the last column. how i can accomplish this.Can i get a simple example of this

Re: Sorting In A Virtual ListControl

Code-o-mat15-Dec-09 2:21

Code-o-mat

15-Dec-09 2:21

As far as i know virtual list controls do not provide you with any means of sorting, you have to do it yourself. If the user clicks a column header you get a LVN_COLUMNCLICK[^] notification from your list control (i don't know about doubleclick, look around List View[^] in MSDN), upon this message you should/need to sort your data yourself (using some nice sorting algorithm like Quick-sort[^]) and then redraw the list items. Good luck.

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Sometimes you just have to hate coding to do it well. <

Accelerators in VC++

VCsamir14-Dec-09 23:21

VCsamir

14-Dec-09 23:21

hi all,

Actaully my Question seems to be silly but i just wanted to know can i set the same key accelerators to two ID's i.e if i have popup menu lock and unlock a object than if my accelerator is Ctrl+L then on first press of Ctrl+L it should lock object and agian on second time keypress it should unlock it... for lock and unlock the id's are different

Thanks

Samir

Re: Accelerators in VC++

Moak15-Dec-09 0:37

Moak

15-Dec-09 0:37

Hi Samir! Assign Ctrl+L to ID_APP_OBJECT_TOGGLE, and write a command handler that toggles the object (lock/unlock object depending on current state). Does that work for you?

Hope it helps.
/M

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Re: Accelerators in VC++

KarstenK15-Dec-09 2:08

KarstenK

15-Dec-09 2:08

write a function ChangeLock() of your object Blush | :O

Press F1 for help or google it.
Greetings from Germany

Re: Accelerators in VC++

Code-o-mat15-Dec-09 2:08

Code-o-mat

15-Dec-09 2:08

You could have 2 accelerator tables, one for lock and one for unlock assigned to Ctrl+L and swap between them when needed, or if you create the accelerator table programatically using CreateAcceleratorTable[^] then you could re-create the table with the new key-command assignments as needed, but i doubt you want to go thorough this trouble to implement an ugly solution. You are probably better off assigning a third command to Ctrl+L whose handler will toggle/negate the current state as someone already suggested.

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Sometimes you just have to hate coding to do it well. <

ActiveX controls child window of another ActiveX control

Miriama2514-Dec-09 22:41

Miriama25

14-Dec-09 22:41

I have an ocx (in visual studio 6, lets call in main ocx) which includes in it a pointer to another ocx (which was written in visual studio 2005, lets call it sub ocx). the main ocx (in Visual Studio 6) has a wrapper for the second ocx which was created by "project->add to project->components and controls", the wrapper is 1 *.cpp file and one *.h file.
In the code in the main ocx, I call "psub = new sub()", and after that I call psub->create(...).
inside create I get crush in file OCCCONT.CPP, at function "BOOL CWnd::InitControlContainer()" at line "m_pCtrlCont = afxOccManager->CreateContainer(this);"
In sub::InitInstance() I call AfxEnableControlContainer() and also in main::InitInstance() I call AfxEnableControlContainer(), as I've read in the internet while I was trying to figure out the problem, but I still get crush.
This is the place to mention that the place where I call "psub = new sub()" and then "psub->create(...)" is inside a static thread. I must keep this call inside the static thread.
In addition, I see that the psub->m_hWnd before psub->create(...) is null.
Does anyone have any idea what to do?
Thanks
Miriam

Re: ActiveX controls child window of another ActiveX control

KarstenK14-Dec-09 23:09

KarstenK

14-Dec-09 23:09

you better use the same Version of Visual Studio for all OCX for compatibility.

Press F1 for help or google it.
Greetings from Germany

Re: ActiveX controls child window of another ActiveX control

Miriama2514-Dec-09 23:16

Miriama25

14-Dec-09 23:16

but the sub ocx uses webservice which is supported only in VS 2005, and the rest of the code, (which is huge projects, milions of code-lines) is in VS 6.
Do you have any other idea?
Thanks

Re: ActiveX controls child window of another ActiveX control

KarstenK14-Dec-09 23:41

KarstenK

14-Dec-09 23:41

Finding the crash course, looks like you need a HWND and havent a valid one. -> Create a Window.

Press F1 for help or google it.
Greetings from Germany

Re: ActiveX controls child window of another ActiveX control [modified]

Miriama2515-Dec-09 1:35

Miriama25

15-Dec-09 1:35

you mean creating a window in the sub ocx or the main one?
or it doesn't matter..
Thanks

modified on Tuesday, December 15, 2009 7:44 AM

Re: ActiveX controls child window of another ActiveX control

KarstenK15-Dec-09 1:57

KarstenK

15-Dec-09 1:57

for solving your writing: "I see that the psub->m_hWnd before psub->create(...) is null."

Press F1 for help or google it.
Greetings from Germany

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