Public Class ValueChangedEventArgs(Of T)
        Inherits System.EventArgs
        Public NewValue As T
        Public OldValue As T
        Public Sub New(ByVal nv As T, ByVal ov As T)
            NewValue = nv
            OldValue = ov
        End Sub
    End Class
 
    Public Class VariableWithEvents(Of T)
        Public Event ValueChanged(ByVal sender As Object, ByVal e As _
          ValueChangedEventArgs(Of T))
        Private _value As T
        Public Property Value() As T
            Get
                Return _value
            End Get
            Set(ByVal value As T)
                RaiseEvent ValueChanged(Me, New ValueChangedEventArgs(Of T)( _
                  value, _value))
                _value = value
            End Set
        End Property
    End Class
 
    Dim WithEvents v1 As New VariableWithEvents(Of String)
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
        v1.Value = "help"
        v1.Value = "Me"
    End Sub
 
    Private Sub v1_ValueChanged(ByVal sender As Object, ByVal e As _
      ValueChangedEventArgs(Of String)) Handles v1.ValueChanged
        Debug.WriteLine("v1 changed, old value=" & e.OldValue & " new value=" & _
        e.NewValue)
    End Sub

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