Problem removing an entry from a collection

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VB

I have a project where I collect plays for a game, and store the details of the play in a listbox /collection. Later, I want to be able to obtain the last play and reverse it, then delete it from the listbox / collection.

My problem is the delete of the listbox works, but the delete of the collection does not work.

Attached is an abbreviated version of the project.

What am I doing wrong?

What I have tried:

The form contains a listbox (ListEntries), two buttons (btnAdd and bthUndo), and a textbox (TxtDisplay)

btnAdd adds a generated entry to the listbox and collection, then displays the result in the textbox.

Each time it is clicked, it adds another entry to the listbox / collection.

btnUndo is supposed to return the LAST entry in the collection, display it, then delete it from the listbox and the collection. Each time it is clicked, it should delete the last entry in the list.

The problem is that the “return” always returns the LAST entry added – period. The listbox entry is deleted, but it appears the collection entry is never deleted. What am I doing wrong.

Class to contain details of each play.

Public Class CEntry
    Public EntrySeq As Integer
    Public EntryTxt As String

    Public Sub add()
        EntrySeq = 0
        EntryTxt = ""
    End Sub

    Public Overrides Function ToString() As String
        Dim display As String
        display = "Play=" + EntrySeq.ToString("D2") +
                 "  EntryText=" + EntryTxt
        Return display
    End Function
End Class

Class to contain collection of plays.

Public Class CCollect
    Inherits CollectionBase

    ' Add a entry to the collection
    Public Sub add(ByRef newentry As CEntry)
        Me.List.Add(newentry)
    End Sub
End Class

Form1 Routines

Public Class Form1

    Dim AddCount As Integer
    Dim SelectIndex As Integer
    Dim SelectSub As Integer

    Dim Entry As New CEntry
    Dim Collect As New CCollect

    Private Sub btnAdd_Click(sender As Object, e As EventArgs) Handles btnAdd.Click
        AddCount += 1
        Entry.EntrySeq = AddCount
        Entry.EntryTxt = "S" + AddCount.ToString("D2")

        'Add the new entry to the Collection
        Collect.add(Entry)
        'add the entry to the listbox
        SelectIndex = ListEntries.Items.Add(Entry)

        TxtDisplay.Text = "Count=" + Collect.Count.ToString("D2") +
            "  Entry=" + Entry.ToString
    End Sub

    Private Sub bthUndo_Click(sender As Object, e As EventArgs) 
Handles bthUndo.Click

        Dim testSelection As New CEntry
        Dim SelectIndex As Integer
        Dim SelectSub As Integer

        SelectSub = Collect.Count          ' Range 1 thru count
        SelectIndex = SelectSub - 1        ' range 0 thru count - 1

        If SelectSub = 0 Then
            Exit Sub
        End If
        testSelection = Nothing
        testSelection = Collect(SelectIndex)

        TxtDisplay.Text = "Count=" + SelectSub.ToString("D2") +
                          "  Entry=" + testSelection.ToString

        ' Remove Selection from ListBox
        ' SelectIndex is in the 0 to count-1 range
        ListEntries.Items.RemoveAt(SelectIndex)

        'Remove Selection from Collection
        Collect.RemoveAt(SelectIndex)

    End Sub
End Class