From: Dominic Sisneros <dsisnero@...>
Date: 2008-06-04T09:04:11+09:00
Subject: win32ole , WIN32OLE_EVENT.new and Microstation Please Help!

I am trying to control a Microstation application through its VBA api.
 I am able
to connect to the object and control it but I am now trying to figure
out how to deal
with Microstation's event handling.  In Microstation VBA you declare
that a class implements
an Event interface and make sure the class implements all the methods.
You then call
a method on the Application object

app = WIN32OLE.new('MicrostationDGN.Application.1')
app.visible = TRUE
app.AddSaveAsEventsHandler SaveHandler

I tried to create a class that implements the methods in 'ISaveAsEvents'

class SaveHandler

def AfterRedraw
end

def BeforeRedraw
end
end

but get a segmentation fault because of type mismatch

I also tried to use the WIN32OLE_EVENT class

ev = WIN32OLE_EVENT.new(app, 'IViewUpdateEvents')

=> No such interface supported



Here is a win32ole_pp of the 'AddSaveAsEventsHandler' method

#<WIN32OLE_METHOD:0x32c7ac4: AddViewUpdateEventsHandler
  name="AddViewUpdateEventsHandler",
  dispid=1610744231,
  helpstring="",
  helpcontext=2674,
  helpfile="C:\\PROGRA~1\\Bentley\\Program\\MICROS~1\\MicroStationVBA.chm",
  invoke_kind="FUNC",
  invkind=1,
  return_type="VOID",
  return_type_detail=["VOID"],
  return_vtype=24,
  size_opt_params=0,
  size_params=1,
  offset_vtbl=1720,
  visible?=true,
  event?=false,
  event_interface=nil,
  params=
   [#<WIN32OLE_PARAM:0x32ad494: EventHandler
      name="EventHandler",
      ole_type="IViewUpdateEvents",
      ole_type_detail=["PTR", "USERDEFINED", "IViewUpdateEvents"],
      default=nil,
      input?=true,
      output?=false,
      optional?=false,
      retval?=false>]>


*********


Here is an example that they show in the help file for Microstation.
the following is the class file

' This is the implementation of clsEventHandlers. It has Implements
statements declaring that it implements anevent interface.



Implements IViewUpdateEvents

'
'  Methods for the IViewUpdateEvents
'
Private Sub IViewUpdateEvents_AfterRedraw(TheViews() As View,
TheModels() As ModelReference, ByVal DrawMode As MsdDrawingMode)
    If UBound(TheModels) < 0 Then
        ' This is a normal update. Everything is being redrawn
    End If
End Sub

Private Sub IViewUpdateEvents_BeforeRedraw(TheViews() As View,
TheModels() As ModelReference, ByVal DrawMode As MsdDrawingMode)

End Sub


******************

Here is how the initialize it.  Everything not declared defaults to
the Application object


Private oEventHandlers As clsEventHandlers

Sub InstallHandlers()
    RemoveHandlers
    Set oEventHandlers = New clsEventHandlers
    AddViewUpdateEventsHandler oEventHandlers
End Sub

Sub RemoveHandlers()
    If Not oEventHandlers Is Nothing Then
        RemoveViewUpdateEventsHandler oEventHandlers
    End If
    Set oEventHandlers = Nothing
End Sub