"Oenone" wrote:

> LCAdeveloper wrote:
>
> > My problem is how do I set the reverse conditions when I close this
> > child form?
>
> You need a reference to the actual instance of your MDI parent form...
>
> > I have tried putting (in the Exit button click event)
> > Toolbar1.Buttons(6).Pushed=False
> > Toolbar1.Buttons(6).Enabled=True
> > but get a syntax error saying that 'name Toolbar1 is not declared.'
>
> I assume this code is within the MDI child form itself. This isn't working
> because it's stating that the Toolbar1 control is within the child form,
> which isn't the case. That's why it says it can't find a declaration for the
> toolbar.
>
> > and even
> > MDIParentFormname.Toolbar1.Buttons(6).Pushed=False
> > MDIParentFormname.Toolbar1.Buttons(6).Enabled=True
> > gives me a syntax error 'Reference to a non-shared member requires an
> > object fererence'.
>
> This isn't working because MDIParentFormname is a class (i.e., a description
> of the MDI Parent form) rather than an object (an actual instance of the MDI
> Parent form).
>
> The easiest way to get a reference to the actual MDI Parent form object is
> to use the MDIParent property of your child form. This must have been set in
> order for your MDI child form to be appearing within the MDI container. So
> for example, in the Closing or Closed event of your child form, try the
> following code:
>
> \\\
>     Me.MDIParent.Toolbar1.Buttons(6).Pushed = False
>     Me.MDIParent.Toolbar1.Buttons(6).Enabled = True
> ///
>
> Hopefully that will do the job.
>
> --
>
> (O) e n o n e
>
>
>

"Oenone" wrote:

> LCAdeveloper wrote:
> > Thanks for your reply. Please forgive my ignorance, but pasting the
> > suggested code into my closing statement produces a syntax error in
> > that 'Me.MdiParent.Toolbar1' is not a member of
> > 'System.Windows.Forms.Form'.
>
> Ah, my bad. Try this in your child form's Closing event (I've actually
> tested it this time so it really should work):
>
> \\\
>     Dim myMDI as Form1
>     myMDI = DirectCast(Me.MdiParent, Form1)
>     myMDI.Toolbar1.Buttons(6).Pushed = False
>     myMDI.Toolbar1.Buttons(6).Enabled = True
> ///
>
> The first line declares a new object pointer whose type is Form1 (i.e., the
> same type as your MDI parent form). It doesn't create an new object, just a
> pointer to an object (which currently points to Nothing).
>
> The second line points the myMDI variable at your MDI parent form, which it
> accesses through the child form's MdiParent property. If you have Option
> Strict On, this will fail with a compilation error, however, so you use
> DirectCast to tell VB that MDIParent actually is of type Form1. (If
> MdiParent were of a different type, this would give you a run-time error
> when it executed, but as you know it will always be a Form1 object this is
> ok). myMDI now points to the actual instance of Form1 that is the MDI
> parent.
>
> Now you have access to the MDI parent instance, you can access its members,
> such as Toolbar1. This will then allow you to perform the updates that you
> need.
>
> Try that and see how you get on this time.
>
> > My orginal MDI container form, let us call this MDIParent Form1,
> > produces a child form with the following code when a menu item is
> > activated:
> > \\\
> > Dim NewMDIChild As New Form2
> > Toolbar1.Buttons(6).Pushed = True
> > NewMDIChild.MdiParent = Me
> > NewMDIChild.Show
> > ///
> >
> > I take it that this means that Form2 is an MDIChild of Form1?
>
> Form2 is a class the describes a form, not an actual instance of a form.
> NewMDIChild is an instance of a form (i.e., a real form that exists on the
> screen), and it is a child of Form1 (due to the fact that it's MdiParent
> property has been set to your MDI parent).
>
> > I'm
> > confused now. Do I have to declare an instance of the toolbar in the
> > child form in able to access it, or am I missing something more
> > fundamental in how Toolbar1 is created?
>
> The difference is that when the MDI parent form talks to Toolbar1 in the
> code you posted above, it is talking within the context of itself. The code:
>
>     Toolbar1.Buttons(6).Pushed = True
>
> ....actually in full is this:
>
>     Me.Toolbar1.Buttons(6).Pushed = True
>
> Because you omit the "Me.", VB looks for a Toolbar1 contained within the
> current object. Because this is the MDI parent and it does contain Toolbar1,
> everything works fine.
>
> However, when you try to run the same code in your MDI child form, the child
> form looks for a control called Toolbar1 within itself. There isn't one
> there of course, because the toolbar is in the MDI parent form, not the MDI
> child form.
>
> The fix is therefore to gain access to the MDI parent form so that you can
> tell it to update its toolbar. This is what the code I posted above is
> doing.
>
> Does that make it any clearer?
>
> --
>
> (O) e n o n e
>
>
>