Exploiting the .NET Validation Frameworks: Listing 3.

The GetErrors method.

Public Function IsValidForCustomerID(value As String, 
                            Notify As Boolean) As Boolean
  Dim NameError As New List(Of String)

  If _Errors.ContainsKey("CustomerID") Then
    If Notify Then 
      RaiseEvent ErrorsChanged(Me, 
        New ComponentModel.DataErrorsChangedEventArgs("CustomerID"))
    End If
  End If

About the Author

Peter Vogel is a system architect and principal in PH&V Information Services. PH&V provides full-stack consulting from UX design through object modeling to database design. Peter tweets about his VSM columns with the hashtag #vogelarticles. His blog posts on user experience design can be found at http://blog.learningtree.com/tag/ui/.