Visual Basic

public sub Constructor()
 
   Dim objName as New Component() ' local variable, not instance member
   objName.OnFunctionCall = new COM_Component_OnFunctionCallEventHandler(AddressOf OnFunctionCall) // delegate

end sub
 
public sub OnFunctionCall() // my delegate
  MsgBox "Test"
end sub

Bastard Programmer from Hell
if you can't read my code, try converting it here[^]

Public Class ABC

  Private objName as New Component() ' Initialized Component

  Public Sub New() ' constructor
    AddHandler objName.OnFunctionCall, AddressOf OnFunctionCall ' assigned function
  End Sub

  Public Overridable Sub OnFunctionCall() ' here is the function
    MessageBox.Show("asd")
  End Sub
End Class

<br />
An unhandled exception of type 'system.stackoverflowexception' occured in 'mscorlib.dll'<br />

AmbiguousName wrote:

What is the difference between the method shown previously and the method I am trying below

Public Class MyThingy
End Class
Public Class ABC
 
  Private Thingy as New MyThingy() ' Initialized Thingy

  Public Sub New() ' constructor
    AddHandler objName.OnFunctionCall, AddressOf OnFunctionCall ' assigned function
  End Sub
 
  Public Overridable Sub OnFunctionCall() ' here is the function
    MessageBox.Show("asd")
  End Sub
End Class

Bastard Programmer from Hell
if you can't read my code, try converting it here[^]

Eddy Vluggen wrote:

"OnFunctionCall" does not exist in the Thingy-class here, but it looks like that's what you'd want.

Eddy Vluggen wrote:

Or is there a special reason for using "Component"?

Public Class MyThingy : Inherits ABC
  Public Overrides Sub OnFunctionCall()
    MsgBox "Hello Universe!!"
  End Sub
End Class
Public Class ABC
 
  Public Sub New() 
  End Sub
 
  Public Overridable Sub OnFunctionCall() 
    MessageBox.Show("Hello world!")
  End Sub
End Class

Public Class MyThingy
  Public Event EventHandler OnMyFunction

  ' call this method and the above event gets fired
  Private Sub TriggerEvent()
    OnMyFunction(Me, EventArgs.Empty)
  End Sub
End Class
Public Class ABC
  Private Thingy as MyThingy()

  Public Sub New() 
    Thingy = New MyThingy
    ' and since we wired the event to a specific method (in this class), 
    AddHandler Thingy.OnMyFunction, AddressOf LocalOnMyFunctionImplementation 
  End Sub
 
  ' causing this method to execute
  Public Overridable Sub LocalOnMyFunctionImplementation(Object as Sender, e As EventArgs)
    MessageBox.Show("asd")
  End Sub
End Class

AmbiguousName wrote:

Just learning it.

Bastard Programmer from Hell
if you can't read my code, try converting it here[^]