collection class with keys?

[kleinma]

I have found a few examples of creating your own collection classes (although they all appear to be ripped off from the original MS one on msdn)

but non of them specify information regarding keys. Does any have an example of a custom collection class in .net using keys instead of indexes? or alongside indexes?

'Copyright (C) 2002 Microsoft Corporation
'All rights reserved.
'THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER 
'EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF 
'MERCHANTIBILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
 
'Requires the Trial or Release version of Visual Studio .NET Professional (or greater).
 
Option Strict On
 
Public Class Customers
 
    ' The first thing to do when building a CollectionBase class is
    ' to inherit from System.Collections.CollectionBase
    Inherits System.Collections.CollectionBase
 
    Public Overloads Function Add(ByVal Value As Customer) As Customer
 
        ' After you inherit the CollectionBase class, 
        ' you can access an intrinsic object
        ' called InnerList that represents your 
        ' collection. InnerList is of type ArrayList.
        Me.InnerList.Add(Value)
        Return Value
 
    End Function
 
    Public Overloads Function Add(ByVal FirstName As String, ByVal LastName As String, ByVal AccountNum As String) As Customer
        Dim cust As New Customer()
 
        cust.FirstName = FirstName
        cust.LastName = LastName
        cust.AccountNumber = AccountNum
 
        ' When you use the InnerList.Add method, you must
        ' pass it an object to add to the collection. In this
        ' case we've created a new Customer object based on
        ' passed parameters, and now we're adding it to the
        ' InnerList.
        Me.InnerList.Add(cust)
 
        Return cust
 
    End Function
 
    Public Overloads Function Item(ByVal Index As Integer) As Customer
 
        ' To retrieve an item from the InnerList, pass
        ' the index of that item to the .Item property.
 
        Return CType(Me.InnerList.Item(Index), Customer)
    End Function
 
    Public Overloads Function Item(ByVal cust As Customer) As Customer
 
        ' To retrieve an item from the InnerList, pass
        ' the index of that item to the .Item property.
 
        Dim myIndex As Integer
 
        myIndex = Me.InnerList.IndexOf(cust)
        Return CType(Me.InnerList.Item(myIndex), Customer)
 
    End Function
 
    Public Overloads Sub Remove(ByVal cust As Customer)
 
        ' To remove an item from the collection, you must
        ' pass in a reference to that item (in this case, the
        ' Customer object we want to remove).
 
        ' However, it is often more convenient to create a
        ' Remove method that allows the calling code to pass in 
        ' only the index of the item instead of an object reference.
        ' So we've overloaded the Remove method to use either one.
        Me.InnerList.Remove(cust)
    End Sub
 
    Public Overloads Sub Remove(ByVal Index As Integer)
 
        ' This is the second Remove method. Instead of passing
        ' in an object reference, this Remove expects an index.
 
        ' The calling code can decide which one to call.
 
        ' If the calling code passes an index, you can simply
        ' look up that item by using the InnerList.Item method,
        ' then remove the item.
 
        Dim cust As Customer
 
        cust = CType(Me.InnerList.Item(Index), Customer)
        If Not cust Is Nothing Then
            Me.InnerList.Remove(cust)
        End If
    End Sub
 
End Class