No-op lambda

Question

I have an event on one of my classes that I want to attach a handler to. However, I don't need the handler to do anything, as I am just testing the behaviour of the class with handlers attached or not.

The event signature is as follows:

public event EventHandler<EventArgs> Foo;

So I want to do something like:

myClass.Foo += ();

However this isn't a valid lambda expression. What is the most succinct way to express this?

Answer 1

(x,y) => {} //oops forgot the params

OK? :)

Or

delegate {}

Answer 2

Try this:

myClass.Foo += delegate {};

Answer 3

Attach the event via a lambda like such:

myClass.Foo += (o, e) => {
    //o is the sender and e is the EventArgs
};

Answer 4

myClass.Foo += (s,e) => {};

or

myClass.Foo += delegate {};

Answer 5

Try this:

myClass.Foo += (s,e) => {};

Answer 6

Rather than attach a delegate afterwards, the more common way is to do assign it immediately:

public event EventHandler<EventArgs> Foo = delegate {};

I prefer using the anonymous method syntax over a lambda expression here as it will work with various different signatures (admittedly not those with out parameters or return values).