Why is "new" operator working for detaching a eventhandler using -=?

Question

Why do I have to use the following to detach an event?

object.myEvent -= new MyEvent(EventHandler);

I am some how irritated that the new operator is working.

Can some one explain?

Update

I already know that i don't have to use the new operator for detaching events, but it is still the auto complete suggestion in Visual Studio 2010. My real question is how does -= new work for the detach process. How can a new object / delegate match a prior created object / delegate on the += side?

Answer 1

You don't have to use the new operator. You haven't had to since C# 2.0 came out:

foo.SomeEvent += EventHandler;
foo.SomeEvent -= EventHandler;

This uses a method group conversion to create a delegate from the method group (the name of the method). This isn't just for events, either:

Action<string> writeToConsole = Console.WriteLine;

EDIT: As for how it works:

• Using -= on an event just ends up calling the "remove" accessor, which typically uses -= on a delegate... (at least effectively)
• Using -= on a delegate is syntactic sugar for Delegate.Remove
• Delegate.Remove uses delegate equality - two delegate instances are equal if they have the same method and the same target instance (for instance methods)

Note that using a method group conversion will still create a new instance of the delegate each time you go through the code.