Event of BaseClass

[Halimaji Nijazi]

Hi newsgroup

I am creating a Mustinheritable Class. From this class I inherit several
other classes.

Now I like to interit the events to, but I can't do this. What am I doing
wrong.

Here is a simple code as sample:

Public MustInherit Class test

Public MustOverride Function testFunct() As Boolean

Public Event testevent()

End Class

Public Class test2

Inherits test

Public Overrides Function testFunct() As Boolean

End Function

End Class


I only want to use the event from the base class, but don't know how...


Thanks for the help...

Regards

Nijazi Halimaji

[ClayB]

Re: Event of BaseClass

Most .NET framework classes have event pattern that provides for a
protected virtual method (OnXXXXX) that actually raises the event
(XXXXX). So, for example, the event Control.MouseDo wn is actually
raised within the library method Control.OnMouse Down which is
protected and virtual. So, in your classes, you could use the same
pattern. You could expose a virtual method that actually raises your
event. Then the inheritors of your class can interact and control the
event through an override.

==============
Clay Burch
Syncfusion, Inc.

[Phill W.]

Re: Event of BaseClass

Halimaji Nijazi wrote:

Hi newsgroup
>
I am creating a Mustinheritable Class. From this class I inherit several
other classes.
>
Now I like to interit the events to, but I can't do this. What am I doing
wrong.

You /do/ inherit the Events but you /can't/ raise them directly from
within a derived class.

The design pattern from Our Friends in Redmond is (as far as I
understand it) to provide a Protected method that raises the event on
behalf of any subclasses, something like:

Public MustInherit Class test

Public MustOverride Function testFunct() As Boolean

Public Event TestEvent( _
ByVal sender As Object _
, ByVal e as EventArgs _
)

Protected Sub OnTestEvent()
RaiseEvent TestEvent( Me, EventArgs.Empty )
End Sub

End Class

Public Class test2
Inherits test

Public Overrides Function testFunct() As Boolean
MyBase.OnTestEv ent()
End Function

End Class

HTH,
Phill W.