Running into an issue with some functionality I'm trying to develop. 

 Client uses a series of Business objects (entities like Order, Customer, etc)  that all inherit from the MustInherit class called AbstractEntity.  There is a desire to add some logging/audit functionality to this class, so that all the objects will have it.  Essentially, we want this:

 --Edits Begin

--A copy of the object is written out via binary serialization

--Properties are changed

Then, there are two paths:

EndEdit is called

--insert entries to logging table

--discard the binary copy

Or

CancelEdit is called

The values in the binary copy should be restored, in effect, discarding the edits

I thought I could implement IEditiableObject  on the AbstractEntity class, since the methods exposed seem to fit perfectly with what we are trying to capture, but I am having difficulty envisioning how to handle the CancelEdit method -- how can I take a Byte() and use it to overwrite the values of the object itself?  Esp. since I'm in the Abstract class, and not a concrete instance.

 For example, the Customer class could have properties like FirstName, LastName, and RegisterDate.  When BeginEdit is called, I make a binary copy of the object, and store it in a private property of the AbstractEntity Class.

  What can I do so that when CancelEditis called, the binary copy is "restored"?

Here is the code of the AbstractEntity class

Option Strict On
Option Explicit On

Imports System.ComponentModel
Imports System.Runtime.Serialization.Formatters.Binary
Imports System.IO

Public MustInherit Class AbstractEntity
    Implements IEditableObject
    'this class contains the common properties that all business objects will share
    'this includes items like the objects state

    Private _state As Integer
    Private _binData As Byte()
    Private _memStream As MemoryStream
    Private _binFormat As BinaryFormatter

    Public Enum ObjectStateEnum As Integer
        UNCHANGED = 0
        CHANGED = 1
        CHANGING = 2
    End Enum

    Sub BeginEdit() Implements IEditableObject.BeginEdit
        'here we will store a serialized version of the object -- before edit
        'Set state to Changing
        _memStream = New MemoryStream
        _binFormat = New BinaryFormatter

        _binFormat.Serialize(_memStream, Me)
        _binData = _memStream.ToArray()
        _state = ObjectStateEnum.CHANGING
    End Sub

    Sub CancelEdit() Implements IEditableObject.CancelEdit
        'we would restore the values of our serialized copy
        _memStream = New MemoryStream(_binData)
        _binFormat = New BinaryFormatter

        _binFormat.Deserialize(_memStream)
        _state = ObjectStateEnum.UNCHANGED
    End Sub

    Sub EndEdit() Implements IEditableObject.EndEdit
        'Accept Edit.  Object has Changed.
        _state = ObjectStateEnum.CHANGED
    End Sub

    Public Property ObjectState() As ObjectStateEnum
        Get
            Return CType(_state, ObjectStateEnum)
        End Get
        Set(ByVal value As ObjectStateEnum)
            _state = value
        End Set
    End Property
    Public ReadOnly Property HasChanges() As Boolean
        Get
            If _state = ObjectStateEnum.CHANGED Then
                Return True
            Else
                Return False
            End If
        End Get
    End Property

End Class

 Code above doesn't include the EndEit implementation, or a full CancelEdit.

TIA