End all running code of .dll

[JakkyTchong]

Hi,

I'm writing a .dll. I'd like to know how to stop all the code running
from anywhere in the solution. For example:
-A class of the .dll is called from an .exe.
-Function A is called from the main sub.
-Function A calls Function B.
-Function B calls Function C.
-I need to terminate all the running code from Function C with a simple
method/function.

Is there an easy way to do this? Sometimes it gets very long to
propagate error handling back tho the main sub when deep into
functions.

I get this error when writing "End": 'End' statement cannot be used in
class library projects.

It seems 'End' statement doesn't work in .dlls...

Any ideas?

JakkyTchong

 

[Phill W.]

-A class of the .dll is called from an .exe.
-Function A is called from the main sub.
-Function A calls Function B.
-Function B calls Function C.
-I need to terminate all the running code from Function C with a simple
method/function.

Is there an easy way to do this? Sometimes it gets very long to
propagate error handling back tho the main sub when deep into
functions.

And that's what Exceptions are all about.

You'll probably need a flag defined at the class level that is read by
the lowest-level function.
When it sees this flag being set, the method throws an Exception.
The Exception is caught and handled by the top-level function, which
then decides what, if anything it can do about it.

Class Z
Private m_bOops As Boolean = False

Sub A()
Try
B()
Catch ex As Exception
Return ' or whatever
End Try
End Sub

Sub B()
C()
End Sub

Sub C()
Do While True
If m_bOops Then
Throw New ApplicationException( "Boom" )
End If
End Do
End Sub

End Class

It seems 'End' statement doesn't work in .dlls...

I would suggest that End is never required.

HTH,
Phill W.

 

[JakkyTchong]

Thanks Phill for the very useful snippet of code. That would work well
I think. Do yo know if it would be possible to do approximately the
same thing using events? I don't have any experience with events at
all. Would it be simple enough to implement?

JakkyTchong

 

[Phill W.]

Do yo know if it would be possible to do approximately the
same thing using events? I don't have any experience with events at
all. Would it be simple enough to implement?

An event can spike a "notification" to some routine that is interested
in it, but can't affect the flow of execution - you can't get out of a
function by raising an event; you can by throwing an Exception.

HTH,
Phill W.

 

[JakkyTchong]

Alright then! An Exception it will be!

Thanks a lot Phill for your help and have a great weekend!

JakkyTchong