Imports System.Console
Namespace NS_OverridesDemo

    Module Demo
        Public Sub Main()
            WriteLine("Overrides Demo")
            WriteLine()

            WriteLine("Base Class...")
            Dim bc As BaseClass = New BaseClass
            bc.Other()
            bc.OverrideMethod()

            WriteLine()
            WriteLine("Derived Class...")
            Dim dc As DerivedClass = New DerivedClass
            dc.Other()
            dc.OverrideMethod()

            ReadLine()
        End Sub
    End Module


    Public Class BaseClass
        Public Overridable Sub OverrideMethod()
            WriteLine("Base OverrideMethod")
        End Sub

        Public Sub Other()   ' Not Overrideable
            WriteLine("Base Other method – not overridable")
        End Sub
    End Class

    Public Class DerivedClass
        Inherits BaseClass

        Public Overrides Sub OverrideMethod()
            ' Or, Public NotOverridable Overrides Sub OverrideMethod()
            WriteLine("Derived OverrideMethod")
        End Sub

        ' Causes Error as sub in Base Class is Not Overrridable
        'Public Overrides Sub Other()
        '
        'End Sub

    End Class

End Namespace