Managing Superseded and Revised Drawings

Currently we do not use a database system like Vault or Project Wise to manage project superseded and revised drawings. Typically we just have a superseded file in the same folder as the production drawing and transfer a copy of a drawing to that folder prior to revising it for whatever reason.
Some times however I forget to make a backup copy of the drawing to the superseded folder. To over come this I put some code together the other day to prompt the user on opening of a drawing weather or not to create a copy to the superseded folder . Here is  dump  of the code that others may find helpful. Currently I append the current date and time to the file name but am looking at prompting for a revision letter or the like.

Imports Autodesk.AutoCAD.Runtime
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.DatabaseServices


Imports System
Imports System.IO

Public Class Class4
    Implements Autodesk.AutoCAD.Runtime.IExtensionApplication
    Private docMan As DocumentCollection = Application.DocumentManager

    <CommandMethod("AddDocColEvent")> _
    Public Sub Initialize() Implements IExtensionApplication.Initialize
        AddHandler docMan.DocumentCreated, AddressOf docMan_DocumentCreated
        DoIt()
    End Sub

    <CommandMethod("RemoveDocColEvent")> _
    Public Sub RemoveDocColEvent()
        RemoveHandler docMan.DocumentCreated, AddressOf docMan_DocumentCreated
    End Sub


    Public Sub Terminate() Implements IExtensionApplication.Terminate

    End Sub


    Sub docMan_DocumentCreated(ByVal sender As Object, ByVal e As DocumentCollectionEventArgs)
        DoIt()
    End Sub


    Private Sub DoIt()
        'check if the drawing has been saved yet or not
        Dim acDoc As Document = Application.DocumentManager.MdiActiveDocument
        Dim strDWGName As String = acDoc.Name

        Dim obj As Object = Application.GetSystemVariable("DWGTITLED")

        '' Check to see if the drawing has been named
        If System.Convert.ToInt16(obj) = 0 Then
            '' If the drawing is using a default name (Drawing1, Drawing2, etc)
            '' then do nothing
        Else
            'Ask the user if they want to save a supercended version of this drawing
            Dim Message As String
            Message = "Save a Superseded version of this drawing."

            Dim style = MsgBoxStyle.YesNoCancel Or MsgBoxStyle.DefaultButton1 Or MsgBoxStyle.Critical
            Dim Title As String
            Title = "Supercended"

            ' Display the message box and save the response, Yes or No.
            Dim response = MsgBox(Message, style, Title)
            Select Case response
                Case 6
                    ' Yes
                    'Get the current drawings path

                    ' Specify the directories you want to manipulate.
                    Dim path As String = DrawingPath()
                    Dim Directory As String = Application.GetSystemVariable("DWGPREFIX") & "Superseded\"

                    'Ask the user if they want to add a suffix or prefix to the file name 
                    ''Dim FormToOpen As Type
                    ''FormToOpen = GetType(Form1)
                    ''Dim frm As Form1 = CType(Activator.CreateInstance(FormToOpen), Form1)
                    ''Autodesk.AutoCAD.ApplicationServices.Application.ShowModalDialog(frm)

                    Dim time As DateTime = DateTime.Now
                    Dim format As String = "yy.MM.dd.HH.mm"
                    Dim timestring As String = (time.ToString(format))

                    Dim path2 As String = Directory & timestring & "_" & Application.GetSystemVariable("DWGNAME")

                    'Check for the supercended folder in the current drawing path
                    'Create directory

                    Try
                        If (Not System.IO.Directory.Exists(Directory)) Then
                            System.IO.Directory.CreateDirectory(Directory)
                        End If

                        'Save a copy of the current drawing
                        ' Copy the file.
                        File.Copy(path, path2)

                    Catch ex As System.Exception
                        MsgBox("Error " & Err.Description & " - " & Err.Number & Convert.ToChar(10))
                        Return
                    End Try

                Case 7
                    'No
                    'Do Nothing
                Case 2
                    'Cancel
                    'Do Nothing
                Case Else
                    MsgBox("Response not recongised")
            End Select
        End If
    End Sub

    Public Function DrawingPath() As String
        Dim doc As Document = Application.DocumentManager.MdiActiveDocument
        Dim hs As HostApplicationServices = HostApplicationServices.Current
        Dim path As String = hs.FindFile(doc.Name, doc.Database, FindFileHint.[Default])
        'doc.Editor.WriteMessage(vbLf & "File was found in: " & path)

        Return path

    End Function

End Class