classes & forms

What is the best way to handle forms with classes?

I want to know/check (in another class) if a form is terminated.
When I use:

dim myfrm as new frm

sub showme
if not myfrm is nothing then frm.show vbmodeless -> is this the way??
end sub

in a class module.

Do I have to work with events then or must I define myfrm
global in a module.

When I use events:
dim withevents myfrm as new frm

sub showme
if not myfrm is nothing then frm.show vbmodeless
end sub

Private Sub myfrm_NotifyTerminate()
??? set myfrm = nothing -> will cause an internall error because it hasn't handled the sub terminate in the form
end sub

If not myfrm is nothing then
'it isn't terminated
else
'it is terminated
end if

Be sure in the class terminate event to set the form to nothing if it isn't terminated yet.

VB Code:

Dim MyForm   As Form1
   Set MyForm = New Form1
   Load MyForm
   MyForm.Show
   Set MyForm = Nothing
   If MyForm Is Nothing then
      'This is the problem, since MyForm is nothing, but it's still visible and loaded into memory :D
      MsgBox "Woooooooooooooooooooooooof"
   End If

Okay, again

1) in the class I show/load the form
2) the user terminates the form
3)later on, the sub showme is called again (by me), so this somehow has to determine if myfrm is/or isn't nothing.

A terminate will cause an unload/visible=false but will not set the object myfrm = nothing
how to accomplish this?

Gotcha :D

In class module

VB Code:

Private MyForm   As Form1
 
Public Sub Show()
   If MyForm Is Nothing Then
      Set MyForm = New Form1
   End If
   MyForm.Show
End Sub
 
Private Sub Class_Terminate()
   Set MyForm = Nothing
End Sub

In Form1

VB Code:

Private Sub Form_Unload(Cancel As Integer)
   Cancel = True
   Me.Hide
End Sub

The problem here is if you destroy the class before the user closes the form, as this would just hide the form and it would stay like that until u turned your PC off :( You would have to add the following in the class terminate event:

VB Code:

Private Sub Class_Terminate()
   If Not MyForm Is Nothing then
      UnLoad MyForm
      Set MyForm = Nothing
   End If
End Sub

Does that make sense?

Is that what you wanted?

Thanks Wokawidget, yes this makes sence.

This is what I wanted to do.
(okay you'll hide instead of setting myform = nothing)

But now my problem is that I'm working (only in this case) with VBA and not VB.

When I hide the object, I can't make it visible again.
(can't acces the properties) .visible=true

Any cluess?

VB Code:

MyForm.Show

:D

That'll do the trick...

Thanks again Wokawidget,

I was using the wrong method-event:

Private Sub UserForm_Terminate
Me.Hide
End Sub

But this unloads the object when invoked.

Prior to this UserForm_QueryClose runs (equals Form_unload)
in form:

Private Sub UserForm_QueryClose(Cancel As Integer, CloseMode As Integer)
Cancel = True
Me.Hide
End Sub

Now the Class.sub.showme works fine.

:D