Do i have to unsubscribe from anonymous event handlers of local variables?

Question

If I have a code that looks something like this:

public void Foo()
{
    Bar bar = new Bar();

    bar.SomeEvent += (sender, e) =>
    {
        //Do somethin         


        

Answer 1

The above answers are correct; I just wanted to make a note. Anonymous delegates used as handlers can only be unsubscribed if you retain some other reference to the delegate/lambda. This is because lambdas are "function literals", kind of like string literals, however unlike strings they are NOT compared semantically when determining equality:

public event EventHandler MyEvent;

...

//adds a reference to this named method in the context of the current instance
MyEvent += Foo;

//Adds a reference to this anonymous function literal to MyEvent
MyEvent += (s,e) => Bar();

...

//The named method of the current instance will be the same reference
//as the named method.
MyEvent -= Foo;

//HOWEVER, even though this lambda is semantically equal to the anonymous handler, 
//it is a different function literal and therefore a different reference,
//which will not match the anonymous handler.
MyEvent -= (s,e) => Bar();

var hasNoHandlers = MyEvent == null; //false

//To successfully unsubscribe a lambda, you have to keep a reference handy:

EventHandler myHandler = (s,e) => Bar();

MyEvent += myHandler;

...

//the variable holds the same reference we added to the event earlier,
//so THIS call will remove the handler.
MyEvent -= myHandler;