anxious! The creation of a modeless dialog box, the second display error! !! !!

没言语

I create a modeless dialog in the View class. Just started
CMyDialog * pDlg = new CMyDialog ();
Then pDlg-> Create (IDD_DIALOG);
pDlg-> ShowWindow (SW_SHOW);
No problem at all, everything works fine.
But the teacher asked later, do not use this, define a MyDialog member variable dlg in View
Then display it with dlg.
I just dlg.Create and dlg.ShowWindow
However, it can be displayed once each time, and an error will be displayed the second time.
why? What should I do? ?
Please master pointing. Thanks thank you very much

爱德华德

The second time can not be created, because it has been created

stormblinger

When the dialog box is closed, you need to call the function to destroy the dialog yourself.

At each create level, determine whether the variable has been associated with a dialog.

wangjiawu

Can be like this: dlg.DoModal ()

stormblinger

Call it at the end
CWnd :: DestroyWindow

mystonelh

The second time can not be created, because it has been created

You can write code like this when creating
if (! dlg)
   dlg.Create (...)
You can't go wrong

爱德华德

tomystonelh

if (! dlg)
   dlg.Create (...)

You are taking a closer look

shizi3650

I support
CWnd::DestroyWindow



But it is placed before Create

没言语

Thank you, all of you.