"Parent" or "Owning" Form of a "Sub-Form"

[eBob.com]

How does a "sub-form", i.e. one invoked by another form, determine anything
about the form which brought it into existence, i.e., I suppose,
instantiated it? I wanted to so something like this ...

MsgBox("called by " & Owner.Name)

.... but that throws a null reference exception. Parent.Name and
ParentForm.Name also throw null reference exceptions. Form1.Name works -
but that's not very flexible.

My MsgBox, above, is in the constructor of the "sub-form".

Thanks, Bob

[rowe_newsgroups]

Re: "Parent&qu ot; or "Owning&qu ot; Form of a "Sub-Form"

On Sep 18, 2:15 pm, "eBob.com" <eBob....@total lybogus.comwrot e:

How does a "sub-form", i.e. one invoked by another form, determine anything
about the form which brought it into existence, i.e., I suppose,
instantiated it?  I wanted to so something like this ...
>
MsgBox("called by " & Owner.Name)
>
... but that throws a null reference exception.  Parent.Name and
ParentForm.Name also throw null reference exceptions.  Form1.Name works-
but that's not very flexible.
>
My MsgBox, above, is in the constructor of the "sub-form".
>
Thanks,  Bob

If you want to show the message box from the constructor, you're most
likely going to need to pass in a reference to the creating from as a
parameter.

I wonder however if you mean you want to know what form showed the
"sub-form". In which case the message box should live in the "Show"
and "ShowDialog " method, but be warned it might only work if you use
the overloaded call that passes in the owning form.

Thanks,

Seth Rowe [MVP]

http://sethrowe.blogspot.com/

[Family Tree Mike]

Re: &quot;Parent&qu ot; or &quot;Owning&qu ot; Form of a &quot;Sub-Form&quot;

If it is an MdiChild, the it can call MdiParent.Name. If as you suggest you
are just doing a ShowDialog type of call, then you could use a StackTrace
object.

"eBob.com" <eBob.com@total lybogus.comwrot e in message
news:uBViGqbGJH A.3392@TK2MSFTN GP05.phx.gbl...

How does a "sub-form", i.e. one invoked by another form, determine
anything about the form which brought it into existence, i.e., I suppose,
instantiated it? I wanted to so something like this ...
>
MsgBox("called by " & Owner.Name)
>
... but that throws a null reference exception. Parent.Name and
ParentForm.Name also throw null reference exceptions. Form1.Name works -
but that's not very flexible.
>
My MsgBox, above, is in the constructor of the "sub-form".
>
Thanks, Bob
>

[eBob.com]

Re: &quot;Parent&qu ot; or &quot;Owning&qu ot; Form of a &quot;Sub-Form&quot;

>"rowe_newsgrou ps" <rowe_email@yah oo.comwrote in message
>news:9588d6b f-a5a6-43ab-b0d7-e5c979d99645@m4 5g2000hsb.googl egroups.com...
>On Sep 18, 2:15 pm, "eBob.com" <eBob....@total lybogus.comwrot e:

>How does a "sub-form", i.e. one invoked by another form, determine
>anything
>about the form which brought it into existence, i.e., I suppose,
>instantiated it? I wanted to so something like this ...
>>
>MsgBox("call ed by " & Owner.Name)
>>
>... but that throws a null reference exception. Parent.Name and
>ParentForm.Nam e also throw null reference exceptions. Form1.Name works -
>but that's not very flexible.
>>
>My MsgBox, above, is in the constructor of the "sub-form".
>>
>Thanks, Bob

>
>If you want to show the message box from the constructor, you're most
>likely going to need to pass in a reference to the creating from as a
>parameter.
>
>I wonder however if you mean you want to know what form showed the
>"sub-form". In which case the message box should live in the "Show"
>and "ShowDialog " method, but be warned it might only work if you use
>the overloaded call that passes in the owning form.
>
>Thanks,
>
>Seth Rowe [MVP]
>http://sethrowe.blogspot.com/

Hi Seth,

What I am after is the name of the form which did the

Dim sform as new SomeForm

i.e. in SomeForm code I want to get the name of who New'ed me. Maybe the
same code will Show me maybe it won't. Maybe it already has maybe it never
will.

Although I ran into the problem in constructor code it seems to me that it
is a general problem. MsgBox has nothing to do with the problem, I was just
using it to experiment and to illustrate the problem. In general I would
say that it is a bad programming practice to try to get at any information
about your creator (unless it is explicitly passed). But I think that there
might be exceptions such as Location (which is what I was after).

What really makes me curious is what Parent, ParentForm, and Owner mean
since not a one of them means what I would have guessed.

Thanks, Bob