Does empty add/remove event definition prevent references?

Question

I'm implementing an interface which defines an event which I don't need/want, but I want to avoid keeping unwitting subscribers 'alive'.

I think that if I define the event explicitly, this should suffice, but will the compiler add code in there and thwart my plans?

public event EventHandler CanExecuteChanged
{
    add { }
    remove { }
}

---

Context: I've had problems with MVVMLight RelayCommand because it uses WeakReference, and apparently I have too much indirection in my code and I'm losing commands. So I want to implement my own CanAlwaysExecuteCommand, for which I don't need the event.

Answer 1

Yes this should work. I use the same trick if an interface forces INotifyPropertyChanged and some of the implementations are immutable.

But I wasn't sure so I tested it using this class:

public class Foo : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged
    {
        add { }
        remove { }
    }
}

The corresponding IL-Code for the event implementation (shown by dotPeek) is:

.method public final hidebysig virtual newslot specialname instance void 
  add_PropertyChanged(
    class [System]System.ComponentModel.PropertyChangedEventHandler 'value'
  ) cil managed 
{
  .maxstack 8

  // [77 17 - 77 18]
  IL_0000: nop          

  // [77 19 - 77 20]
  IL_0001: ret          

} // end of method Foo::add_PropertyChanged

.method public final hidebysig virtual newslot specialname instance void 
  remove_PropertyChanged(
    class [System]System.ComponentModel.PropertyChangedEventHandler 'value'
  ) cil managed 
{
  .maxstack 8

  // [78 20 - 78 21]
  IL_0000: nop          

  // [78 22 - 78 23]
  IL_0001: ret          

} // end of method Foo::remove_PropertyChanged

.event [System]System.ComponentModel.PropertyChangedEventHandler PropertyChanged
{
  .addon instance void ConsoleApplication1.Foo::add_PropertyChanged(class [System]System.ComponentModel.PropertyChangedEventHandler) 
  .removeon instance void ConsoleApplication1.Foo::remove_PropertyChanged(class [System]System.ComponentModel.PropertyChangedEventHandler) 
} // end of event Foo::PropertyChanged