Hi,

is it possible to pass a callback function from VB6 to VB.NET? I've tried
the following and got the error "Function pointer was not created by a
Delegate.".

______________________________
' VB.NET class library: Biblioteca.Class1

Imports System.Runtime.InteropServices
Imports System.Threading

Public Interface IClass1
   Delegate Sub EndSomething_EventHandler()
   Sub StartSomething(<MarshalAs(UnmanagedType.FunctionPtr)> ByVal
callbackFunction As IClass1.EndSomething_EventHandler)
End Interface

Public Class Class1
   Implements IClass1

   Public Sub StartSomething(ByVal callbackFunction As
IClass1.EndSomething_EventHandler) Implements IClass1.StartSomething
       Thread.Sleep(5000)
       If Not callbackFunction Is Nothing Then
           callbackFunction.DynamicInvoke(Nothing)
       Else
           MsgBox("No callback function was received.", MsgBoxStyle.Critical)
       End If
   End Sub

End Class
______________________________
' V6 standard exe

' ---- Form1.frm ----
Option Explicit

Private Sub Command1_Click()
   StartProcess
End Sub

' ---- Module1.bas ----

Option Explicit

Public Sub StartProcess()
   Dim objVBNET As Biblioteca.IClass1
   Set objVBNET = CreateObject("Biblioteca.Class1")
   objVBNET.StartSomething AddressOf ShowMessage
End Sub

Public Sub ShowMessage()
   MsgBox "This is the VB6 callback function.", vbExclamation
End Sub