Binding Combobox to Object Datasource - vb.net

Question

I've got a form bound to an object datasource. It has one text box and one combo box. I set up one binding source for the main object and one binding source for the combo box. When I run the form, the text box is bound correctly, and the list of values in the combo box is bound correctly, but the ValueMember of the combo box isn't working correctly.
The combo box shows the correct list, but it's selected index is 0 instead of what it should be 2. When I change the value in the text box, it's bound object's Property.Set method is called correctly, but the same Property.Set method is not called for the combo box.
I know I can hack up the OnSelectedIndex change methods in the form, but I would like to know what I am doing wrong in just using the Bindings.
Here is the code on the form:
Public Class Form1
Private Sub Form1_Load(sender As Object, e As System.EventArgs) Handles Me.Load
Dim NameValueBindingSource1 As New BindingSource()
Dim WorkOrderBindingSource1 As New BindingSource
'Create main object to bind to
Dim wo As New WorkOrder
wo.WOIndex = "2012-0111"
wo.WorkOrderType = 3
'Create list object for combo box
Dim NameValues As BindingList(Of NameValue)
NameValues = FillNameValueList()
'Bind Text Box to Binding Source
WorkOrderBindingSource1.DataSource = wo
WOIndexTextBox1.DataBindings.Add("Text", WorkOrderBindingSource1, "WOIndex")
'Bind Combo Box to Binding Source
NameValueBindingSource1.DataSource = NameValues
WorkOrderTypeCombo.DataSource = NameValueBindingSource1
WorkOrderTypeCombo.DisplayMember = "Value"
WorkOrderTypeCombo.ValueMember = "Code"
End Sub
Function FillNameValueList() As BindingList(Of NameValue)
Dim bl As New BindingList(Of NameValue)
Dim nv As NameValue
nv = New NameValue
bl.Add(New NameValue("Short", 0))
bl.Add(New NameValue("Middle", 1))
bl.Add(New NameValue("Long", 2))
bl.Add(New NameValue("Very Long", 3))
Return bl
End Function
End Class
Here's the code for the main object - "WorkOrder"
Imports System.ComponentModel
Public Class WorkOrder
Implements IEditableObject
Implements INotifyPropertyChanged
Private mWOIndex As String
Private mWorkOrderType As Integer
Public Event PropertyChanged(sender As Object, e As System.ComponentModel.PropertyChangedEventArgs) Implements System.ComponentModel.INotifyPropertyChanged.PropertyChanged
Public Property WOIndex As String
Get
Return mWOIndex
End Get
Set(value As String)
mWOIndex = value
RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs("WOIndex"))
End Set
End Property
Public Property WorkOrderType As Integer
Get
Return mWorkOrderType
End Get
Set(value As Integer)
mWorkOrderType = value
RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs("WorkOrderType"))
End Set
End Property
Public Sub BeginEdit() Implements System.ComponentModel.IEditableObject.BeginEdit
End Sub
Public Sub CancelEdit() Implements System.ComponentModel.IEditableObject.CancelEdit
End Sub
Public Sub EndEdit() Implements System.ComponentModel.IEditableObject.EndEdit
End Sub
End Class
Here's the code for the object used in the combo box
Imports System.ComponentModel
Public Class NameValue
Implements IEditableObject
Implements INotifyPropertyChanged
Private mValue As String
Private mCode As Integer
Public Event PropertyChanged(sender As Object, e As System.ComponentModel.PropertyChangedEventArgs) Implements System.ComponentModel.INotifyPropertyChanged.PropertyChanged
Public Property Code As Integer
Get
Return mCode
End Get
Set(value As Integer)
mCode = value
RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs("Code"))
End Set
End Property
Public Property Value As String
Get
Return mValue
End Get
Set(value As String)
mValue = value
RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs("Value"))
End Set
End Property
Public Sub BeginEdit() Implements System.ComponentModel.IEditableObject.BeginEdit
End Sub
Public Sub CancelEdit() Implements System.ComponentModel.IEditableObject.CancelEdit
End Sub
Public Sub EndEdit() Implements System.ComponentModel.IEditableObject.EndEdit
End Sub
Public Sub New(InitValue As String, InitCode As Integer)
Value = InitValue
Code = InitCode
End Sub
End Class

Answer 1

In your code, you are merely assigning the DataSource to the ComboBox, but you're not establishing any DataBinding for it.
You need a line like this (using C# here):
WorkOrderTypeCombo.DataBindings.Add(new System.Windows.Forms.Binding("SelectedValue", WorkOrderBindingSource1, "WorkOrderType", true));
Hope this helps