Public Class TrapMessage 
   Inherits MessageBase

Dim instance As TrapMessage

public class TrapMessage : MessageBase 

public __gc class TrapMessage : public MessageBase 

public ref class TrapMessage : public MessageBase 

private void button1_Click(object sender, EventArgs e)
{
  //Start listening for traps, notifications and informs
  manager1.Start(manager1_MessageReceived, null);
}

private void manager1_MessageReceived(Manager manager, MessageBase message, object state)
{
  //Marshal message to the UI thread using the Message event
  if (message is TrapMessage)
    manager.Marshal(new MessageBase[] { message }, "trap");
    else if (message is NotificationMessage)
    manager.Marshal(new MessageBase[] { message }, "notification");
  else if (message is InformMessage)
  {
    manager.Marshal(new MessageBase[] { message }, "inform");

    //Send response to inform message origin
    manager.Send(new ResponseMessage(message as InformMessage), message.Origin);
  }
}

private void manager1_Message(object sender, MessageEventArgs e)
{
  //Update interface according to message type received
  switch (e.UserState.ToString())
  {
    case "trap":
      TrapMessage trap = e.Messages[0] as TrapMessage;
      label1.Text = "Trap received with Enterprise(" + trap.Enterprise + "), Generic Type (" +
        trap.GenericTrap.ToString() + "), Specific Type(" + trap.SpecificTrap.ToString() + ")";
      break;
    case "notification":
      NotificationMessage notification = e.Messages[0] as NotificationMessage;
      label1.Text = "Notification received with OID (" + notification.Oid + ")";
      break;
    case "inform":
      InformMessage inform = e.Messages[0] as InformMessage;
      label1.Text = "Inform received with " + inform.Variables.Count.ToString() + " variable(s).";
      break;
  }
}

Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles button1.Click
  'Start listening for traps, notifications and informs
  manager1.Start(AddressOf manager1_MessageReceived, Nothing)
End Sub

Private Sub manager1_MessageReceived(ByVal manager As Manager, ByVal message As MessageBase, ByVal state As Object)
  'Marshal message to the UI thread using the Message event
  If TypeOf message Is TrapMessage Then
    manager.Marshal(New MessageBase() {message}, "trap")
  ElseIf TypeOf message Is NotificationMessage Then
    manager.Marshal(New MessageBase() {message}, "notification")
  ElseIf TypeOf message Is InformMessage Then
    manager.Marshal(New MessageBase() {message}, "inform")

    'Send response to inform message origin
    manager.Send(New ResponseMessage(TryCast(message, InformMessage)), message.Origin)
  End If
End Sub

Private Sub manager1_Message(ByVal sender As Object, ByVal e As MessageEventArgs) Handles manager1.Message
  'Update interface according to message type received
  Select Case e.UserState.ToString()
    Case "trap"
      Dim trap As TrapMessage = TryCast(e.Messages(0), TrapMessage)
      label1.Text = "Trap received with Enterprise(" & trap.Enterprise & "), Generic Type (" & _
        trap.GenericTrap.ToString() & "), Specific Type(" & trap.SpecificTrap.ToString() & ")"
    Case "notification"
      Dim notification As NotificationMessage = TryCast(e.Messages(0), NotificationMessage)
      label1.Text = "Notification received with OID (" & notification.Oid & ")"
    Case "inform"
      Dim inform As InformMessage = TryCast(e.Messages(0), InformMessage)
      label1.Text = "Inform received with " & inform.Variables.Count.ToString() & " variable(s)."
  End Select
End Sub