The following may be in the right direction. First I used a few language extension methods e.g.
Public Module BindingSourceExtensions
<Runtime.CompilerServices.Extension()>
Public Function DataTable(ByVal sender As BindingSource) As DataTable
Return CType(sender.DataSource, DataTable)
End Function
<Runtime.CompilerServices.Extension()>
Public Sub AddCustomer(ByVal sender As BindingSource, ByVal FirstName As String, ByVal LastName As String)
sender.DataTable.Rows.Add(New Object() {Nothing, FirstName, LastName})
End Sub
<Runtime.CompilerServices.Extension()>
Public Function DetachedTable(ByVal sender As BindingSource) As DataTable
Return CType(sender.DataSource, DataTable).GetChanges(DataRowState.Detached)
End Function
<Runtime.CompilerServices.Extension()>
Public Function AddedTable(ByVal sender As BindingSource) As DataTable
Return CType(sender.DataSource, DataTable).GetChanges(DataRowState.Added)
End Function
End Module
Now load ID, FirstName and LastName into a DataTable, Datatable becomes the DataSource of a BindingSource which is the BindingSource for a BindingNavigator and are wired up to a DataGridView.
Keeping things simple I mocked up data, has no assertions e.g. make sure we have valid first and last name, instead concentrate on the methods.
First use a extension method to add a row to the underlying DataTable of the BindingSource.
bsCustomers.AddCustomer("Karen", "Payne")
Now check to see if there are detached or added rows
Dim detachedTable As DataTable = bsCustomers.DetachedTable
If detachedTable IsNot Nothing Then
Console.WriteLine("Has detached")
Else
Console.WriteLine("No detached")
End If
Dim AddedTable As DataTable = bsCustomers.AddedTable
If AddedTable IsNot Nothing Then
Console.WriteLine("Has added")
Else
Console.WriteLine("None added")
End If
Since we are not talking to the database table, the primary key is not updated as expected and since you don't want to update the database table this is fine. Of course there is a method to get the primary key for newly added records if you desire later in your project.
Addition
Private Sub BindingSource1_AddingNew(ByVal sender As System.Object, ByVal e As System.ComponentModel.AddingNewEventArgs) Handles BindingSource1.AddingNew
Dim drv As DataRowView = DirectCast(BindingSource1.List, DataView).AddNew()
drv.Row.Item(0) = "some value"
e.NewObject = drv
' move to new record
'BindingSource1.MoveLast()
End Sub
