Question

In C# what is the advantage of

public class blah {         public event EventHandler Blahevent;  } 

versus

public class blah {        private event EventHandler blahevent;        public event EventHandler Blahevent       {           add               {                   blahevent+=value;               }                remove               {                   blahevent-=value               }       }  } 

or vice versa.

does the first one open you up to blahinstance.Blahevent = null, or blahinstance.Blahevent(obj,even)

Answer 1

There is no advantage to explicit implementation of the add/remove methods unless you want to do something different. Possible reasons:

• Perhaps take control of the event backing code yourself (to directly link to some other event rather than going though a pointless cascade for example)
• do something else in addition on add or remove
• Change security demands on the add or remove
• expose the underlying delegate

What the default implementation does is maintain a private hidden delegate field which is replaced each time a delegate is added or removed. For most cases there is no need to do any of the above but the flexibility is there.