Passing variables to dialogs

Posted on 1998-12-21
Last Modified: 2010-04-02
I am using VC++ 5.0 and have written a program in Dialog mode. I have a Main Dialog and several other dialogs that open when I click a button.

I know how to pass variables from the other Dialogs to the Main Dialog by using this:


Since m_dlg is the reference it uses to refer to the Dialog and m_Variable is the variable name, how do I pass a variable from the Main Dialog to the other Dialogs?

Question by:randyg
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Accepted Solution

Answers2000 earned 50 total points
ID: 1180779
When you declare the 2nd, 3rd, 4th dialog you must have

(a) Defined a scratch variable
CSecondDlg dlg2 ;
dlg2.DoModal() ;

In this case insert code between these 2 lines
CSecondDlg dlg2 ;
dlg2.m_value = 5 ;
dlg2.DoModal() ;


(b) Added the second dialog as a class member of the first, e.g. m_dlg2 is a member of CFirstDlg

Then you can do
m_dlg2.m_variable = 99 ; // or whatever


Author Comment

ID: 1180780
Thanks for the answer, but I don't think that I did a very good job explaining the question.

I have a Main Dialog and three other Dialogs that open everytime I click on three buttons.
In the CFilenameDlg.h I added this to declare the each of the three dialogs:

class CMy3170_serial_portDlg : public CDialog
// Construction
      CMy3170_serial_portDlg(CWnd* pParent = NULL);      // standard constructor

      CFirstDlg m_dlg0;         // I added this
      CSecondDlg m_dlg1;    // I added this
      CThirdDlg m_dlg2;        // I added this

So now when ever I am in the Main Dialog and want to pass a variable from either one of these Dialogs I use this :


But the problem I am having is when I'm in one of the three Dialogs and I want to get a Variable from the Main Dialog I can't seem to do this since I didn't declare the Main Dialog as anything. Where do I declare it? How do I declare it? How do I call it into the other Dialogs?


Expert Comment

ID: 1180781
That would be my question as well,  is this your question?

MAINDIALOG: ----> 3 others.

you can't get MAINDIALOG variables when in the 3 others;

BUT you can get 3 others variable when in MAINDIALOG;

My question is the same, exept I used Database and I have mainfrm.

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Expert Comment

ID: 1180782
you could something like this:
CFirstDlg ::set_parent( CMy3170_serial_portDlg *Parent) {
   m_pparent = Parent;
   m_cfirstdlg_variable = m_pparent.m_maindlg_varialbe;
you need some way to reference CMy3170_serial_portDlg  in your dialog classes.  the above is one way and there are many others, i believe this will be the least painful.


Expert Comment

ID: 1180783
I work around this problem in this way.
Include the maindialog.h file in each of the child dialog classes.
wherever you want to access the maindialog's variables, you can do this:
      CMainDialog *mdlg=(CMainDialog *)GetParent();
thanks. hope this helps.
merry christmas to you all.

Expert Comment

ID: 1180784
Merry Christmas to you guys as well.

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