Question

In C# if I want to create a ‘Custom Event’ you do something like this:

private EventHandler _MyEvent; Public Event EventHandler MyEvent  {    add{ _MyEvent += value; }    remove{ _MyEvent -= Value; } } protected void RaiseMyEvent() {    if(_MyEvent != nul)       _MyEvent(this, EventArgs.Empty); } 

In VB this is not so straightforward nor can I find any help ANYWHERE on the net. This does not work:

private _MyEvent as EventHandler Public Custom Event MyEvent as EventHandler    AddHandler(ByVal value as EventHandler)       _MyEvent += value 'does not work       addhandler _MyEvent, value 'does not work       [Delegate].Combine(_MyEvent, value) '_MyEvent still nothing    End AddHandler    RemoveHandler(ByVal value as EventHandler)       'Same kind of stuff here    End RemoveHandler    RaiseEvent(sender as Object, e as EventArgs)       if(_MyEvent IsNot Nothing) Then '_MyEvent is always nothing          _MyEvent.Invoke(sender, e)       End If    End RaiseEvent End Event 

Please help.

Answer 1

Delegates are immutable, so method ‘[Delegate].Combine’ returns new delegate, but not modify the parameters. So you need:

_MyEvent = [Delegate].Combine(_MyEvent, value)