C# – Create empty C# event handlers automatically

c++clrdelegatesevents

It is not possible to fire an event in C# that has no handlers attached to it. So before each call it is necessary to check if the event is null.

if ( MyEvent != null ) {
  MyEvent( param1, param2 );
}

I would like to keep my code as clean as possible and get rid of those null checks. I don't think it will affect performance very much, at least not in my case.

MyEvent( param1, param2 );

Right now I solve this by adding an empty inline handler to each event manually. This is error prone, since I need to remember to do that etc.

void Initialize() {
  MyEvent += new MyEvent( (p1,p2) => { } );
}

Is there a way to generate empty handlers for all events of a given class automatically using reflection and some CLR magic?

Best Solution

I saw this on another post and have shamelessly stolen it and used it in much of my code ever since:

public delegate void MyClickHandler(object sender, string myValue);
public event MyClickHandler Click = delegate {}; // add empty delegate!

//Let you do this:
public void DoSomething() {
    Click(this, "foo");
}

//Instead of this:
public void DoSomething() {
    if (Click != null) // Unnecessary!
        Click(this, "foo");
}

* If anyone knows the origin of this technique, please post it in the comments. I really do believe in the source getting due credit.

(Edit: I got it from this post Hidden Features of C#?)