Passing data between subforms of type CDialog

Question

I have a MS Visual C++ 2005 project where I am trying to have a main dialog box with a section devoted to displaying selectable subform dialogs boxes. Each subform will be of the same size but have a different layout. The selection is performed using a combo-box control. I searched on the best way to implement this functionality and I came across this class that someone developed in 1999 for handling child dialogs within a main dialog:

http://www.codeproject.com/KB/dialog/childdlg.aspx

With the additional modification:

http://www.codeproject.com/KB/dialog/childdlg.aspx?msg=1287#xx1287xx

The code works quite well for selecting and displaying the various subforms but I don’t seem able to pass data from one subform to another. Specifically each subform is comprised of several edit controls. I would like to have the user be able to enter a value in an edit control on Subform #1 and for this value to be echoed in an edit control or static text control on Subform #2.

I tried implementing this by using a member function of the subform dialog class (named CSubFormType and a subclass of CDialog) that would execute upon killing the focus to the data input edit control (i.e. Box1a).

void CSubFormType::OnEnKillfocusBox1a(){

p2WndControl = (CWnd*)(GetDlgItem(IDC_Box1a));  //Get pointer to the control dialog box for data entry

//Inserted here some specific code used to place data entered into IDC_Box1a into extern wchar_t outstr[32]

SetDlgItemText (IDC_Box1b, outstr);  //Echo data entered in IDC_Box1a to IDC_Box1b on same Subform #1


SetDlgItemText (IDC_Box2, outstr);//Echo data entered in IDC_Box1a to IDC_Box2 on different subform, Subform #2

}

The message map for CSubFormType meant to call OnEnKillfocusBox1a directly is:

ON_EN_KILLFOCUS(IDC_Box1a, &CSubFormType:: OnEnKillfocusBox1a)

Or indirectly by:

ON_BN_CLICKED(IDOK, &CSubFormType::OnBnClickedOk) // CSubFormType::OnBnClickedOk then calls OnEnKillfocusBox1a

The problems I am having are:

1) ON_BN_CLICKED(IDOK, &CSubFormType::OnBnClickedOk) does not get called upon hitting Enter key after typing data into Box1a. Instead the OnBnClickedOk member function of the main dialog box gets called instead.

2) When CSubFormType::OnEnKillfocusBox1a does get executed (by mouse click elsewhere) it is able to echo the value entered in Box1a to Box1b on the same Subform #1 but will not echo the value to Box2 on Subform #2.

Any guidance as to what I need to do to resolve these problems or a better approach to implementing the same general functionality would be greatly appreciated.

Combo box selection member function for main dialog box being used:

void CMain::OnCbnSelchange() { int selection;

selection = ((CComboBox*)GetDlgItem(IDC_Select))->GetCurSel();

switch(selection)
{
    case 0: // Select Subform 1
        //Do nothing
        break;

    case 1: // Select Subform 2
        SetDlgItemText (IDC_Box2, outstr); //Set Box2 text on Subform #2
        break;
 }

m_SubForms.ShowSubForm(selection);

}

Answer 1

Synchronize all forms when main combobox selection is changed. You try to make this immediately when textbox text is changed, but it is not necessary because only one form is visible.