>Hi,
>Thank you for sharing. It is actually what I am looking for. However, may I know if that is any code change required to subscribe to event after implement WeakEvent and WeakDelegate?

TBH, I've never implemented this pattern in Winforms - I looked at it in WPF which has a WeakEventManager class that does most of the plumbing for you and is already used by the infrastructure for a lot of binding operations (plug for WPF!).

There seem to be several implementations written for Winforms by various people and I've no idea how well any of them work - but I think they all require different code for wiring up events. I'd suggest only implementing this when you *know* there will be a problem - which may well be a lot less often than you first think.

The project loadable at the bottom of this page shows a working example for that implementation: http://blog.codeinreview.com/post/2008/11/27/NET-EVENTS-(Part-3-A-Weak-Solution).aspx

HTH,
Viv