get-object-value.vb

Class MyEventArgs
    Property Value As Object
End Class

Structure MyStruct
    Public X, Y As Integer
End Structure

Module Program

    Sub Main()

        Dim defaultValue As Object = New MyStruct With {.X = 3, .Y = 5}
        Dim e = New MyEventArgs With {.Value = defaultValue}

        RaiseEvent DoSomething(Nothing, e)

        If e.Value Is defaultValue Then
            ' No handlers have changed anything.
            Console.WriteLine("Unchanged.")
        End If

    End Sub

    Event DoSomething(sender As Object, e As MyEventArgs)

End Module