Problem implementing data binding with DataGridView

Hi guys,
This question is related to my previous question "https://www.experts-exchange.com/questions/22734276/Problem-implementing-data-binding-with-DataGridView.html". As the initial question was answered, and me having additional issues, I decided to open (this) new question.

The code below shows an example that I'm using to data-bind a DataGridView control with an object collection. To run this code just create a Form with a DataGridView control and two buttons (called grdCustomers, btnObjectAddRow and btnDGVAddRow), that I use to: 1) add a new object to the collection and 2) add a row to the DatGridView control.

I am able to (programmatically) delete & modify data/rows via either DataGridView and the Collection bject however I can only add rows via the underlying data and not the DataGridView. When I try to add a row into DataGridView (using button btnDGVAddRow) I get an error message "Rows cannot be programmatically added to the DataGridView's rows collection when the control data-bound".

/Michael

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Imports System.ComponentModel ' Needed for using <Bindable(True)>

Public Class frmCustomers
    Dim Customers As New CustomersList

    Private Sub frmCustomers_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Try
            LoadCustomers()
            Me.grdCustomers.DataSource = Customers
            Me.grdCustomers.Refresh()
        Catch ex As Exception
            MsgBox("Error in '" & Mid(ex.StackTrace, InStrRev(ex.StackTrace, "\") + 1) & "' - " & ex.Message, MsgBoxStyle.Exclamation)
        End Try
    End Sub

    Private Sub LoadCustomers()
        Try
            Dim l As IList = CType(Customers, IList)
            For n As Int16 = 1 To 5
                l.Add(ReadCustomer(l.Count))
            Next
        Catch ex As Exception
            MsgBox("Error in '" & Mid(ex.StackTrace, InStrRev(ex.StackTrace, "\") + 1) & "' - " & ex.Message, MsgBoxStyle.Exclamation)
        End Try
    End Sub

    Private Function ReadCustomer(ByVal n As Int16, Optional ByVal bEmpty As Boolean = False) As Customer
        Dim cust As New Customer(Customers)
        If bEmpty = False Then
            cust.FirstName = "First" & n
            cust.LastName = "Last" & n
        End If
        Return cust
    End Function

    Private Sub grdCustomers_CancelRowEdit(ByVal sender As Object, ByVal e As System.Windows.Forms.QuestionEventArgs)

    End Sub

    Private Sub grdCustomers_CellBeginEdit(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellCancelEventArgs)

    End Sub

    Private Sub grdCustomers_CellEndEdit(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs)

    End Sub

    Private Sub grdCustomers_CellEnter(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs)

    End Sub

    Private Sub grdCustomers_CellLeave(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs)

    End Sub

    Private Sub btnObjectAddRow_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnObjectAddRow.Click
        Dim cust As New Customer(Me.Customers)
        cust.FirstName = "First" & Me.grdCustomers.Rows.Count + 1
        cust.LastName = "Last" & Me.grdCustomers.Rows.Count + 1
        Me.Customers.Insert(Me.grdCustomers.CurrentRow.Index, cust)
    End Sub

    Private Sub btnObjectDeleteRow_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnObjectDeleteRow.Click
        Me.Customers.RemoveAt(Me.grdCustomers.CurrentRow.Index)
    End Sub

    Private Sub btnObjectModifyRow_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnObjectModifyRow.Click
        With Me.Customers.Item(Me.grdCustomers.CurrentRow.Index)
            If Me.grdCustomers.CurrentCell.ColumnIndex = 0 Then
                .LastName = .LastName & Format(Now, "ss")
            Else
                .FirstName = .FirstName & Format(Now, "ss")
            End If
        End With
    End Sub

    Private Sub btnDGVAddRow_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDGVAddRow.Click
        With Me.grdCustomers.CurrentCell
            Try
                Me.grdCustomers.Rows.Insert(Me.grdCustomers.CurrentCell.RowIndex)
            Catch ex As Exception
                MsgBox("Error in '" & Mid(ex.StackTrace, InStrRev(ex.StackTrace, "\") + 1) & "' - " & ex.Message, MsgBoxStyle.Exclamation)
            End Try
        End With
    End Sub

    Private Sub btnDGVDeleteRow_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDGVDeleteRow.Click
        Me.grdCustomers.Rows.RemoveAt(Me.grdCustomers.CurrentRow.Index)
    End Sub

    Private Sub btnDGVModifyRow_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDGVModifyRow.Click
        With Me.grdCustomers.CurrentCell
            .Value = .Value & Format(Now, "ss")
        End With
    End Sub

    Private Sub btnObjectReset_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnObjectReset.Click
        Customers.Clear()
        LoadCustomers()
    End Sub

    Private Sub btnDGVReset_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDGVReset.Click
        Me.grdCustomers.Rows.Clear()
        LoadCustomers()
    End Sub

End Class




Public Class CustomersList
    Inherits BindingList(Of Customer)

    Friend Sub CustomerChanged(ByVal cust As Customer)
        Dim index As Integer = Me.IndexOf(cust)
        OnListChanged(New ListChangedEventArgs(ListChangedType.ItemChanged, index))
    End Sub

End Class




Public Class Customer
    Implements IEditableObject
    Implements INotifyPropertyChanged

    Public Event PropertyChanged(ByVal sender As Object, ByVal e As System.ComponentModel.PropertyChangedEventArgs) Implements System.ComponentModel.INotifyPropertyChanged.PropertyChanged

    Structure CustomerData
        Friend firstName As String
        Friend lastName As String
    End Structure

    Private custData As CustomerData
    Private backupData As CustomerData
    Private inTxn As Boolean = False

    Sub BeginEdit() Implements IEditableObject.BeginEdit
        If Not inTxn Then
            Me.backupData = custData
            inTxn = True
        End If
    End Sub

    Sub CancelEdit() Implements IEditableObject.CancelEdit
        If inTxn Then
            custData = backupData
            inTxn = False
        End If
    End Sub

    Sub EndEdit() Implements IEditableObject.EndEdit
        If inTxn Then
            backupData = New CustomerData()
            inTxn = False
        End If
    End Sub

    Public Sub New(ByVal objMyParent As CustomersList)
        _MyParent = objMyParent
        custData = New CustomerData()
        custData.firstName = ""
        custData.lastName = ""
    End Sub

    Public Sub New()

    End Sub

    Public Property FirstName() As String
        Get
            Return custData.firstName
        End Get
        Set(ByVal Value As String)
            custData.firstName = Value
            Me.OnCustomerChanged()
            Dim PropName As String = System.Reflection.MethodBase.GetCurrentMethod.Name
            RaiseEvent PropertyChanged(Me, New System.ComponentModel.PropertyChangedEventArgs(PropName.Remove(0, 4)))
        End Set
    End Property

    Public Property LastName() As String
        Get
            Return custData.lastName
        End Get
        Set(ByVal Value As String)
            custData.lastName = Value
            Me.OnCustomerChanged()
            Dim PropName As String = System.Reflection.MethodBase.GetCurrentMethod.Name
            RaiseEvent PropertyChanged(Me, New System.ComponentModel.PropertyChangedEventArgs(PropName.Remove(0, 4)))
        End Set
    End Property

    Private _MyParent As CustomersList
    Friend Property MyParent() As CustomersList
        Get
            Return _MyParent
        End Get
        Set(ByVal Value As CustomersList)
            _MyParent = Value
            Dim PropName As String = System.Reflection.MethodBase.GetCurrentMethod.Name
            RaiseEvent PropertyChanged(Me, New System.ComponentModel.PropertyChangedEventArgs(PropName.Remove(0, 4)))
        End Set
    End Property

    Private Sub OnCustomerChanged()
        If Not inTxn And Not (_MyParent Is Nothing) Then
            _MyParent.CustomerChanged(Me)
        End If
    End Sub

End Class