calling form

[Darin]

I have a program that (for example), has form A that opens form B that
opens form C, and form C calls a function, and that function calls a
sub. From that last sub, i need to know if came specifically from form C
(and not form A or B).

Is that possible? If so, how? Some more information, form A is in my
EXE, form B and C are in a DLL, and the function and sub are in
different DLLs than the forms.

Darin

 

[rowe_newsgroups]

I have a program that (for example), has form A that opens form B that
opens form C, and form C calls a function, and that function calls a
sub. From that last sub, i need to know if came specifically from form C
(and not form A or B).

Is that possible? If so, how? Some more information, form A is in my
EXE, form B and C are in a DLL, and the function and sub are in
different DLLs than the forms.

Darin

*** Sent via Developersdexhttp://www.developersdex.com***

Wow, reading that was really confusing. My first suggestion would be
to find another way to do what you want to do. If it's difficult to
explain when you post to the newsgroups, you can be it will be hard to
explain to the maintenance programmer. And a confused maintenance
programmer = wasted time and money.

But if you absolutely need to know who called the method, you could
follow the same approach used in the .NET events, pass in a "sender As
Object" parameter. If you do that you could easily inspect what/who
called the method.

Thanks,

Seth Rowe [MVP]

 

[Darin]

My example might have looked confusing, but it actaully isn't.

I have an application that is started w/ an EXE. Within the EXE it opens
a ut.dll that has a main menu in it. If the user selects customer file,
the customer file is in an ar.dll. Now, i have MANY subs and functions
in a standard libs.dll that can be called from anyplace in my program.

THat is basically what i want - from a sub or function in my libs.dll, i
want to knwo the form that called it.

You suggestion was the one i had though of, i just didn't know if it
was/is included in a trace or something, since when the sub/function
exits it has to know where to go back to.

Darin

 

[Phill W.]

I have a program that (for example), has form A that opens form B that
opens form C, and form C calls a function, and that function calls a
sub. From that last sub, i need to know if came specifically from form C
(and not form A or B).

Why should the Sub /care/ who called it?
Each method should have a specific purpose and, as far as possible,
should be able to "get on with it" without having to "go back" to its
caller for anything.

You have two choices:

(1) Pass the calling Form [all the way] through to the Sub, then you can
interrogate it there.

Sub LastSub( ByVal callingForm as Form )
If TypeOf callingForm is FormC Then
' Form 'C'-specific implementation
. . .
End If
End Sub

(2) Is the Sub /really/ a separate, library routine or is it a function
of each Form and that behaves differently for each one?
If so, Then you need to be thinking of adding that Sub /into/ each of
the Forms, using either Inheritance or an Interface, whichever you prefer.

Class FormA
Public Overridable Sub LastSub()
' "default" implementation here
End Sub
End Class

Class FormB
Inherits FormA

' No override, so just uses the "default" implementation
' from FormA

End Class

Class FormC
Inherits FormA

Public Overrides Sub LastSub()
' 'C'-specific implementation here
End Sub

End Class

HTH,
Phill W.