C / C++ / MFC

8-Jun-06 0:48

Hi I added a class in my MFC dialog based project. Now i want to declare a pointer object of my dialog class in .cpp file of newly added class to access members of dialog class in that cpp file. I declared that pointer like this

CFileSenderDlg *fsD = new CFileSenderDlg;

But program crashes at the point where i use this pointer to access a member function of dialog class. What it the mistake i am doing? Can anyone please help me in this regard?
Thank you.

We Believe in Excellence
www.aqueelmirza.cjb.net

Sarath C8-Jun-06 0:55

8-Jun-06 0:55

The code seems very clean.
1. Check whether the pointer get allocated properly or not (NULL or Junk value).
2. Check for the missing resources, which hadn' is not removed on deleting the control.
3. Check the message handlers

Sa^Rath.

"Don't Do Different things... Do Things Differently..."

Understanding State Pattern in C++

Aqueel8-Jun-06 1:10

8-Jun-06 1:10

Sorry i was wrong. In fact error occures when i try to declare the pointer.
When i tried to debug it, It took me to afxwin1.inl and current pointer was on following lines. Can you please tell me what is the problem?

_AFXWIN_INLINE HINSTANCE AFXAPI AfxGetResourceHandle()<br />
	{ ASSERT(afxCurrentResourceHandle != NULL);

We Believe in Excellence
www.aqueelmirza.cjb.net

Sarath C8-Jun-06 2:11

8-Jun-06 2:11

Sorry for the late reply.

Walk ur call stack and find from where this call occurs.
check for missing resources that may be the problem

Sa^Rath.

"Don't Do Different things... Do Things Differently..."

Understanding State Pattern in C++

khan++8-Jun-06 1:12

khan++

8-Jun-06 1:12

Aqueel wrote:
CFileSenderDlg *fsD = new CFileSenderDlg;

After this, you should create the dialog box also like:
fsD->Create(IDD_WHATEVER,Parent);

Also check that the actual dialog resource is really present by looking at the resource view, and then checking the ID for the dialog.

this is this.

User defined buttons on the MessageBoxes

Hamid_RT8-Jun-06 1:46

Hamid_RT

8-Jun-06 1:46

See here

<br />
CTest::CTest(CWnd* pParent /*=NULL*/)<br />
	: CDialog(CTest::IDD, pParent)<br />
{<br />
	Create(CTest::IDD,pParent);<br />
}<br />
--------------------<br />
CTest	  *m_Test;<br />
m_Test=new CTest(this);<br />

whitesky

Taruni8-Jun-06 0:47

Taruni

8-Jun-06 0:47

Hi

Right now I am working with MessageBoxes.Is there a way to define my own Buttons for the MessageBox with a caption of my wish and handle the ButtonClicked event?

Thanks in advance

Taruni

Re: User defined buttons on the MessageBoxes

khan++8-Jun-06 1:20

khan++

8-Jun-06 1:20

I don't think that is easily possible with the default messagebox. However, you can create a custom message box by defining your own dialog box resource, and returning the proper values from it (EndDialog (VALUE_HERE) ) under different buttons, with everything under your control (caption, focus, text size etc), and using it with its DoModal() function.

this is this.

Re: User defined buttons on the MessageBoxes

Viorel.8-Jun-06 1:29

Viorel.

8-Jun-06 1:29

Even if there are some methods for affecting the standard system’s message box (see, for instance, http://www.codeproject.com/cpp/dMsgBox.asp[^]), I think you should consider creating of your own dialog, with buttons you need.

Re: User defined buttons on the MessageBoxes

Nishad S8-Jun-06 1:36

Nishad S

8-Jun-06 1:36

I think this could help you Smile | :)

http://www.codeproject.com/dialog/CPPMessageBox.asp[^]

- NS -

about friend function

Aqueel8-Jun-06 0:43

Re: about friend function [modified]

8-Jun-06 0:43

Hi friends
I want to ask if i declare a function like

friend ostream& operator<<(ostream& , date&); in a class declaration. Does it become friend function of that class. Can it access private members of class? If yes how i should define it in .cpp file of that class?

Thank you

We Believe in Excellence
www.aqueelmirza.cjb.net

toxcct8-Jun-06 0:52

8-Jun-06 0:52

Aqueel wrote:
Does it become friend function of that class

yes, that's why the friend keyword is made for.

Aqueel wrote:
it access private members of class?

~~no. friend functions/classes access at most protected members (and of course public ones), but not private.~~
yes...

Aqueel wrote:
If yes how i should define it in .cpp file of that class?

you declare it in the class which it is a friend of :

class CMyClass {
    //....
 
  public:
    friend ostream& operator << (ostream&, date&);
};

and then, define it in a .cpp (generally, in the .cpp which defines your class' members) :

ostream& CMyClass::operator << (ostream& os, date& d) {
    //...
    return os;
}

TOXCCT >>> GEII power

[VisualCalc 3.0 updated ][Flags Beginner's Guide new! ]

-- modified at 7:04 Thursday 8th June, 2006

Sarath C8-Jun-06 1:01

8-Jun-06 1:01

toxcct wrote:
Aqueel wrote:
it access private members of class?

no. friend functions/classes access at most protected members (and of course public ones), but not private.

It is wrong.
you can access private members using friend function.

Sa^Rath.

"Don't Do Different things... Do Things Differently..."

Understanding State Pattern in C++

Cedric Moonen8-Jun-06 1:03

Cedric Moonen

8-Jun-06 1:03

toxcct wrote:
no. friend functions/classes access at most protected members (and of course public ones), but not private.

Wrong, it can access also private members (otherwise, this would be stupid): source[^]

Cédric Moonen
Software developer

Charting control

toxcct8-Jun-06 1:05

8-Jun-06 1:05

yes, i've just checked msdn too Wink | ;)

TOXCCT >>> GEII power

[VisualCalc 3.0 updated ][Flags Beginner's Guide new! ]

Sarath C8-Jun-06 1:08

8-Jun-06 1:08

What was there inside the MSDN? I think there is nothing saying in MSDN about a friend function accessing private and public or protected!!!

Sa^Rath.

"Don't Do Different things... Do Things Differently..."

Understanding State Pattern in C++

Sarath C8-Jun-06 1:10

8-Jun-06 1:10

From MSDN:

In some circumstances, it is more convenient to grant member-level access to functions that are not members of a class or to all functions in a separate class. The friend keyword allows a function or class to gain access to the private and protected members of a class. You can declare friend functions or friend classes to access not only public members but also protected and private class members.

Check it here!!![^]

Sa^Rath.

"Don't Do Different things... Do Things Differently..."

Understanding State Pattern in C++

Cedric Moonen8-Jun-06 1:13

Cedric Moonen

8-Jun-06 1:13

. I just posted this link in the post above...

Cédric Moonen
Software developer

Charting control

Sarath C8-Jun-06 1:17

8-Jun-06 1:17

Didnt notcie it

Sa^Rath.

"Don't Do Different things... Do Things Differently..."

Understanding State Pattern in C++

toxcct8-Jun-06 2:03

8-Jun-06 2:03

and what does the last sentence you quoted means for you ???

"You can declare friend functions or friend classes to access not only public members but also protected and private class members."

TOXCCT >>> GEII power

[VisualCalc 3.0 updated ][Flags Beginner's Guide new! ]

Aqueel8-Jun-06 1:04

8-Jun-06 1:04

Thanks for responding.

I have declared function in class decalaration like this

class date <br />
{<br />
private:<br />
....    //private members<br />
....<br />
....<br />
public:<br />
date(int=1, int =1, int =1900);<br />
friend ostream& operator<<(ostream& , date&);<br />
}

Now i define this function is .cpp file like this

ostream& date::operator<<(ostream&o, date& a)<br />
{<br />
	o<<year<<month<<day<<endl;<br />
	return o;<br />
}

but it gives me this error,
error C2039: '<<' : is not a member of 'date'

Why this error is occuring?
Thanks

We Believe in Excellence
www.aqueelmirza.cjb.net

toxcct8-Jun-06 1:06

8-Jun-06 1:06

because the class date must also override the << operator...

TOXCCT >>> GEII power

[VisualCalc 3.0 updated ][Flags Beginner's Guide new! ]

Aqueel8-Jun-06 1:11

8-Jun-06 1:11

Sorry toxcct, I could not get your point. Can you please explain it? Thank you.

We Believe in Excellence
www.aqueelmirza.cjb.net