GC and event handlers question

  • Thread starter Thread starter Chris DiPierro
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Chris DiPierro

Let's say I do the following:

Object A lives "forever" and periodically creates instances of Object B.

Object B triggers events, that Object A registers for immediately upon
the creation of Object B.

Object B is later dereferenced.

Do my handlers to the now dereferences Object B ever get garbage
collected? Or should I explicitly unregister for the events before I
dereference Object B?
 
Chris DiPierro said:
Let's say I do the following:

Object A lives "forever" and periodically creates instances of Object B.

Object B triggers events, that Object A registers for immediately upon
the creation of Object B.

Object B is later dereferenced.

Do my handlers to the now dereferences Object B ever get garbage
collected? Or should I explicitly unregister for the events before I
dereference Object B?
Click to expand...

That depends really on what you mean by the second part. If you mean:

a.SomeEvent += new EventHandler (b.SomeMethod);

then you need to remove that delegate from the event before b can be
garbage collected.

If you mean:

b.SomeEvent += new EventHandler (a.SomeMethod);

then you don't need to do anything.

Basically, the event has a reference to the target of the delegate, but
not the other way round.
 
If you mean:
b.SomeEvent += new EventHandler (a.SomeMethod);
Click to expand...

Yes, this is what I meant.
then you don't need to do anything.

Basically, the event has a reference to the target of the delegate, but
not the other way round.
Click to expand...

Ok, that's what I thought, but I saw some indication to the contrary in
something I was reading.

Thanks for the help.
 
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