Doing extra initialisations on a MFC Dialog in Visual Studio C++ 2008 Pro

Question

How do I make extra initializations on a modal dialog before calling DoModal(); ?

The whole application is created using VS wizards. I have a main Dialog (the one that is created automatically when I select new MFC Application in Visual Studio 2008 Professional).
When I click a button on this dialog I want to open another dialog and set a CString value into a CEdit control.

my code:

...
void MainDlg::OnClickedButtonX(){
   SecondDialogClass Dlg2;
   Dlg2.asocVar2Cedit.SetWindowTextW(L"my text");
   Dlg2.DoModal();
}
//asocVar2Cedit is the associeted control variable to the 
//CEdit control on the second Dialog (Right Click > Add Variable..  in VSC++)
...

this code generates at runtime a "Debug Assertion" error in winocc...

Any ideas ?
Thank you in advance.

Answer 1

Add an OnInitDialog (WM_INITDIALOG) handler to your CDialog-derived class and have it initialise itself.