VB.Net, Closing and discarding a form

Giobib
#1 / 4

Closing and discarding a form

I have two forms: MDIForm and ChildForm.

To open the child form from the MDI I do:

Dim f As frmChildForm
If IsNothing(f) Then
f = New frmChildForm()
f.MdiParent = Me
End If
f.Show()

where f is a module variable.

But if I close the ChildForm whith Me.Close and then I try to open it
again, I get problem, because f si not Nothing.
From the other site, I cannot remove the IF...THEN that avoids two
instances of the same form.

Any suggestion?

Thank you.
Gio

Tue, 26 Apr 2005 19:35:50 GMT

Armin Zingle
#2 / 4

Closing and discarding a form

Quote:

> I have two forms: MDIForm and ChildForm.

> To open the child form from the MDI I do:

> Dim f As frmChildForm
> If IsNothing(f) Then
> f = New frmChildForm()
> f.MdiParent = Me
> End If
> f.Show()

> where f is a module variable.

> But if I close the ChildForm whith Me.Close and then I try to
> open it again, I get problem, because f si not Nothing.
> From the other site, I cannot remove the IF...THEN that avoids two
> instances of the same form.

> Any suggestion?

Dim WITHEVENTS f As frmChildForm
If IsNothing(f) Then
f = New frmChildForm()
f.MdiParent = Me
End If
f.Show()

sub f_closed (...) handles f.closed
f = nothing
end sub

Armin

Tue, 26 Apr 2005 20:09:55 GMT

Giobib
#3 / 4

Closing and discarding a form

On Fri, 8 Nov 2002 13:09:55 +0100, "Armin Zingler"

Quote:

>Dim WITHEVENTS f As frmChildForm
> If IsNothing(f) Then
> f = New frmChildForm()
> f.MdiParent = Me
> End If
> f.Show()

>sub f_closed (...) handles f.closed
> f = nothing
>end sub

But f is a local variable of the MdiParent form.
If I do f=nothing in the closed event of the child form (f) I get the
error message:
"'frmMethod' is a type and cannot be used as an expression."
:-(

Tue, 26 Apr 2005 22:21:43 GMT

Armin Zingle
#4 / 4

Closing and discarding a form

Quote:

> On Fri, 8 Nov 2002 13:09:55 +0100, "Armin Zingler"

> >Dim WITHEVENTS f As frmChildForm
> > If IsNothing(f) Then
> > f = New frmChildForm()
> > f.MdiParent = Me
> > End If
> > f.Show()

> >sub f_closed (...) handles f.closed
> > f = nothing
> >end sub

> But f is a local variable of the MdiParent form.
> If I do f=nothing in the closed event of the child form (f) I
> get the error message:
> "'frmMethod' is a type and cannot be used as an expression."
> :-(

The code is in the MDIparent.

Armin

Tue, 26 Apr 2005 23:21:34 GMT