When an MFC dialog is hidden after DoModal, are its controls destroyed?

Question

I've used MFC dialogs before where you do:

EnterNameDlg dlg;
dlg.DoModal();
string str = dlg.GetName();

However a dialog I have now actually looks at a list-box control in such a method and it's not working. Although the class instance clearly exists after DoModal() , does the actual dialog get destroyed? I noticed calling DoModal() a 2nd time leads to OnInitDialog() also being called again which seems to support this theory, the dialog is recreated from the template rather than simply made visible the 2nd time.

Answer 1

Yes, DoModal creates a dialog on each call and destroys the window before returning.

Only the data members will still be valid. Of course, you can add more data members in your EnterNameDlg class if you want to collect data during dialog's lifetime.
As soon as the dlg gets out of scope, everything will be deallocated.

Answer 2

After DoModal class instance still exists, but window and all its controls are destroyed. You can call only functions that don't work with dialog controls after DoModal. Inside of the dialog class, keep required values in class members like CString, when OK button is pressed. These members can be read after dialog is closed.

Answer 3

The entirety of MFC is built around an awkward pairing - the Windows window with its associated handle, and the MFC class object. The MFC classes are designed to outlast the window in most cases.