Polymorphic : MustInherit « Class Module « VB.Net Tutorial

1. VB.Net Tutorial
2. Class Module
3. MustInherit

Imports System.Collections

public class MustOverrideMustInherit
   public Shared Sub Main
        Dim ShapeArray As New ArrayList()
        ShapeArray.Add(New Cone())
        ShapeArray.Add(New Cube())
        ShapeArray.Add(New Cylinder())
        ShapeArray.Add(New Rectangle())
        Dim shape As Shape
        For Each shape In ShapeArray
            Console.WriteLine(shape.DrawMe())
        Next
   End Sub

End class

Public MustInherit Class Shape
    Public MustOverride Function DrawMe() As String
End Class

Public Class Cone
    Inherits Shape
    Public Overrides Function DrawMe() As String
        Return "Drawing Cone..."
    End Function
End Class
Public Class Rectangle
    Inherits Shape
    Public Overrides Function DrawMe() As String
        Return "Drawing Rectangle..."
    End Function
End Class
Public Class Oval
    Inherits Shape
    Public Overrides Function DrawMe() As String
        Return "Drawing Oval..."
    End Function
End Class
Public Class Cylinder
    Inherits Shape
    Public Overrides Function DrawMe() As String
        Return "Drawing Cylinder..."
    End Function
End Class
Public Class Cube
    Inherits Shape
    Public Overrides Function DrawMe() As String
        Return "Drawing Cube..."
    End Function
End Class

Drawing Cone...
Drawing Cube...
Drawing Cylinder...
Drawing Rectangle...