System.Collections.ObjectModel.KeyedCollection

As an ASP.NET devloper dabbling in the world of WindowsForms I am stumped.

I have created a class and implemented INotifyPropertyChanged on each of the
properties. I have then created a collection inheriting from
KeyedCollection. My problem is I don't know how to consume the events raised
by the items in the collection so I can set the collection's dirty flag.

Can someone help please. Many thanks,

Nick


*********************************************************
Imports System.ComponentModel

Public Class stsTrap
Implements INotifyPropertyChanged

Public Event PropertyChanged As PropertyChangedEventHandler Implements
INotifyPropertyChanged.PropertyChanged

Private Sub NotifyPropertyChanged(ByVal info As String)
RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(info))
End Sub

Private mstrOID As String
Private mstrDesc As String
Private mstrMib As String
Private mintSeverity As Int16 = 1
Private mbIsDirty As Boolean = False

Public Sub New()
End Sub

Public Property OID() As String
Get
Return mstrOID
End Get
Set(ByVal value As String)
'TODO - Do validation checks here
If Not value.Equals(mstrOID) Then
mstrOID = value
mbIsDirty = True
NotifyPropertyChanged("OID")
End If
End Set
End Property

Public Property Description() As String
Get
Return mstrDesc
End Get
Set(ByVal value As String)
'TODO - Do validation checks here.
If Not value.Equals(mstrDesc) Then
mstrDesc = value
mbIsDirty = True
NotifyPropertyChanged("Description")
End If
End Set
End Property

Public Property MIB() As String
Get
Return mstrMib
End Get
Set(ByVal value As String)
'TODO - Do validation checks here.
If Not value.Equals(mstrMib) Then
mstrMib = value
mbIsDirty = True
NotifyPropertyChanged("MIB")
End If
End Set
End Property

Public Property Severity() As Int16
Get
Return mintSeverity
End Get
Set(ByVal value As Int16)
If value < 1 Or value > 99 Then
Throw New ArgumentOutOfRangeException("value", value, "Trap severity
must be between 1 and 99")
End If
If Not value.Equals(mintSeverity) Then
mintSeverity = value
mbIsDirty = True
NotifyPropertyChanged("Severity")
End If
End Set
End Property

End Class


Public Class stsTraps
Inherits System.Collections.ObjectModel.KeyedCollection(Of String, stsTrap)

Private mbIsDirty As Boolean = False

Protected Overrides Function GetKeyForItem(ByVal item As stsTrap) As String
Return item.OID
End Function

Protected ReadOnly Property IsDirty() As Boolean
Get
Return mbisdirty
End Get
End Property

End Class