Is a Multicast Delegate Immutable?

Question

Is a multicast delegate immutable or mutable? Also one more question: is a multicast delegate implemented based on singleton or multiton pattern?

Answer 1

Yes, delegates are immutable. Combining or removing delegates creates a new instance that contains one or more delegates. Delegate references are shared across threads, so there's no threading model to consider. Some frameworks require the delegate to execute in the originating thread, though, so be careful of that.