Imports System.Console
Namespace NS_MustInheritDemo

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

            WriteLine("Base Class...")
            'Causes Error because Base Class has 'MustInherit'     
            '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 MustInherit Class LikeAnInterface
        Public MustOverride Overloads Sub OverrideMethod()
        Public MustOverride Overloads Sub Paint()
        Public MustOverride Overloads Sub SetText(ByVal Text As String)
    End Class

    Public MustInherit Class BaseClass
        Public MustOverride Overloads Sub OverrideMethod()

        Public Sub Other()
            WriteLine("Base Other method")
        End Sub
    End Class

    Public Class DerivedClass ' if you use MustInherit then children will pay
        Inherits BaseClass

        ' Causes Error with missing 'Overrides'
        'Public Sub OverrideMethod()
        '    WriteLine("Derived OverrideMethod")
        'End Sub

        ' If Sub is not defined then the 'MustInherit' is violated
        Public Overrides Sub OverrideMethod()
            WriteLine("Derived OverrideMethod")
        End Sub

    End Class

End Namespace