C / C++ / MFC

27-Oct-05 15:07

Hi!

I'm currently making a project in VC++ (MFC) and when suddenly, I encoutered upon this problem. I compiled by program, and tried to execute it. There were no error messages that pop-upped but the app was not running either. So, I debugged the program and stumbled upon an Access Violation on this part:

CxxxxDlg dlg;<br />
m_pMainWnd = &dlg;                  // here<br />
int nResponse = dlg.DoModal();<br />

So, I tried tracing those lines and never got a clue on how to fix it. Until I renewed the project, imported the resources. I ran it and it works well. But, when I added the class the I wrote, the error came up again. I figured out that the error must be in the class. The code in the constructor in the class when the error came up was:

CTristramCore::CTristramCore()<br />
{<br />
	initConstants();<br />
}<br />

I removed the code in the constructor and the error disappeared...

It's really wierd. Does anyone know why it is so? Blush | :O

Prakash Nadar27-Oct-05 16:22

27-Oct-05 16:22

It would depend on what initConstants is doing!

-prakash
Learning Symbian | Personal views

NeverFall27-Oct-05 16:54

27-Oct-05 16:54

Ahh.. this is what initConstants do:

void CTristramCore::initConstants()<br />
{<br />
	// Init getBotAngle Data<br />
	alBotAngle[0] = 4681;  // 1<br />
	alBotAngle[1] = 29671; // 2<br />
	alBotAngle[2] = 29647; // 3<br />
	alBotAngle[3] = 23497; // 4<br />
	alBotAngle[4] = 31183; // 5<br />
	alBotAngle[5] = 18927; // 6<br />
	alBotAngle[6] = 29257; // 7<br />
	alBotAngle[7] = 31727; // 8<br />
	alBotAngle[8] = 31689; // 9<br />
<br />
	// Init getWindMagnitude Data<br />
	alWindMagnitude[0] = 22730421; // 1<br />
	alWindMagnitude[1] = 28687063; // 2<br />
	alWindMagnitude[2] = 28687723; // 3<br />
	alWindMagnitude[3] = 33553771; // 4,9<br />
	alWindMagnitude[4] = 32202091; // 5<br />
	alWindMagnitude[5] = 32202751; // 6<br />
	alWindMagnitude[6] = 28683627; // 7<br />
	alWindMagnitude[7] = 33554431; // 8,0<br />
}

All it does is set values in an array (-.-)

kakan27-Oct-05 19:36

kakan

27-Oct-05 19:36

And alBotAngle has got 9 elements?
And alWindMagnitude has got 8 elements?

prasad_som27-Oct-05 19:43

prasad_som

27-Oct-05 19:43

Just some checks.
both arrays are having 9 and 8 elements respectively. Is it intentional?(
One very optimistic way, try to comment line one by one Smile | :)

-- modified at 1:44 Friday 28th October, 2005

Oh ! O! I've same suggestion as Kakan

Prakash Nadar27-Oct-05 20:11

27-Oct-05 20:11

NeverFall wrote:
All it does is set values in an array (-.-)

How is alBotAngle and alWindMagnitude defined in the class?

-prakash
Learning Symbian | Personal views

NeverFall27-Oct-05 20:48

27-Oct-05 20:48

They're defined as private.

Declaration:

long alBotAngle[9];<br />
long alWindMagnitude[8];

Prakash Nadar27-Oct-05 21:24

27-Oct-05 21:24

CxxxxDlg dlg;<br />
m_pMainWnd = &dlg; // here<br />
int nResponse = dlg.DoModal();<br />
<br />
CTristramCore::CTristramCore()<br />
{<br />
initConstants();<br />
}

how is CTristramCore initiated in the dialog class?

Sorry, i am asking too many questions, just trying to get to the Root cause Smile | :)

-prakash
Learning Symbian | Personal views

NeverFall27-Oct-05 21:30

27-Oct-05 21:30

It is declared in the dialog class under the private section:

<br />
private:	<br />
	// Functions<br />
	static UINT SetToTop(LPVOID pParam);<br />
	void SetToTopEx();<br />
<br />
	void updateFireAxis(int iFireAxis);<br />
	void initiateMainCall();<br />
<br />
	//Variables<br />
	CTristramCore CoreEngine;<br />
<br />
	bool m_bRunning;<br />
	bool m_bTransparencySupported;<br />
};

Prakash Nadar27-Oct-05 22:49

Dialog Question and Combo/List Box Question

27-Oct-05 22:49

Seems to be very weird, I tried to replicate the logic on my system and I did not get any access violation.

There could be more complex problem.

the statement you said where the exception occurs, seems to be safe.

I am kinda giveing up on this due to less informtion tht I have about your project than you have. Sorry about that.

I suspect if there is something to do with the LHS pointer.

apologies again.

-prakash
Learning Symbian | Personal views

LighthouseJ27-Oct-05 12:02

LighthouseJ

27-Oct-05 12:02

I've tried to find help on here and I didn't find the answer, or recognized when something did tell me the answer.

First, the dialog question. When I create an SDI or MDI project, the document that's created just has a white space which I draw in. I want to replace that with a tree control and I don't know how to do that. Is that white space something set and called for somewhere or is it just a void? I want to put a tree control in it's place (bevel and all) and I don't see where to do that.

Second, the combo/list box question. How do I make a custom list box like the one in Windows SP2's available wireless network dialog. Under it says "Choose a wireless network" and each large item is in a list box of sorts but it has all kinds of things inside. How do I make that, it won't be as complex as that, but it'll be too complex than just text. I figure I'll override the combo box class but I can't find any info on how to actually do it all.

Thanks in advance, Nate.

Christian Graus27-Oct-05 13:00

Christian Graus

27-Oct-05 13:00

LighthouseJ wrote:
I want to replace that with a tree control and I don't know how to do that

I forget the name of it, but the class you derive your view from should be something like CFormView, and then you get a dialog template you can put controls on for the view.

Christian Graus - Microsoft MVP - C++

rahulv27-Oct-05 13:05

rahulv

27-Oct-05 13:05

As far as your first question goes. The View that you are having is a normal view where u draw. If you want to put a Tree Control in there, you have couple of ways to achieve that.
1. You can try using CFormView and in the dialog box u can have tree ctrl view.
2. If you want a drawing view also with this view, you can put a frame in it and make it the parent of another view.
You can do lot of different stuff just by using child parent relationship and types of views. You would be surprised to see what all. Just try a little innovation and creativity and you have it.

Second question I am not sure exactly what you are trying to achieve. In any case you can create your own activeX control which contains both list ctrl and combo box etc. You can combine both of them with no big difficulty. If you are specific I would be able to help you.

LighthouseJ27-Oct-05 14:24

LighthouseJ

27-Oct-05 14:24

To clarify the second question...

The standard list box is just filled with a line of text. I'm looking to build a list box like the one used in the list of wireless networks box in Windows. In there, each item has a couple text items and pictures. Another example would be the Add/Remove Programs dialog, where it has the program icon, the title of the software package, more text elements and a button or two. I want to make each item taller, fill it with multiple text items and possibly a picture. I'm thinking I could just derive a class from the regular tree view, and proceed but I don't know what to do.

ps. I'm investigating CFormView now, thanks to Christian Gaus and yourself.

Christian Graus27-Oct-05 15:00

Christian Graus

27-Oct-05 15:00

LighthouseJ wrote:
CFormView

Yay - I got it right !!!

LighthouseJ wrote:
I want to make each item taller, fill it with multiple text items and possibly a picture.

You can derive a class from the tree view, and make it owner drawn. That means you write the code to show the text and image, at whatever height you like ( well, you can change the height of a menu item, I assume you can do it for a tree item also ).

Christian Graus - Microsoft MVP - C++