Brige in VB.NET

   1:      ' Bridge Design Pattern.

   2:      ' See description in //www.vb-net.com/ProgramTheory/Bridge.htm

   3:      Class MainApp

   4:          ' Entry point into console application.

   5:          Public Shared Sub Main()

   6:              Dim ab As Abstraction = New RefinedAbstraction()

   7:              ' Set implementation and call

   8:              ab.Implementor = New ConcreteImplementorA()

   9:              ab.Operation()

  10:              ' Change implemention and call

  11:              ab.Implementor = New ConcreteImplementorB()

  12:              ab.Operation()

  13:              ' Wait for user

  14:              Console.ReadKey()

  15:          End Sub

  16:      End Class

  17:   

  18:      ' The 'Abstraction' class

  19:      Class Abstraction

  20:          Protected _implementor As Implementor

  21:          ' Property

  22:          Public WriteOnly Property Implementor() As Implementor

  23:              Set(value As Implementor)

  24:                  _implementor = value

  25:              End Set

  26:          End Property

  27:          Public Overridable Sub Operation()

  28:              _implementor.Operation()

  29:          End Sub

  30:      End Class

  31:      ' The 'Implementor' abstract class

  32:      MustInherit Class Implementor

  33:          Public MustOverride Sub Operation()

  34:      End Class

  35:   

  36:      ' The 'RefinedAbstraction' class

  37:      Class RefinedAbstraction

  38:          Inherits Abstraction

  39:          Public Overrides Sub Operation()

  40:              _implementor.Operation()

  41:          End Sub

  42:      End Class

  43:   

  44:      ' The 'ConcreteImplementorA' class

  45:      Class ConcreteImplementorA

  46:          Inherits Implementor

  47:          Public Overrides Sub Operation()

  48:              Console.WriteLine("ConcreteImplementorA Operation")

  49:          End Sub

  50:      End Class

  51:   

  52:      ' The 'ConcreteImplementorB' class

  53:      Class ConcreteImplementorB

  54:          Inherits Implementor

  55:          Public Overrides Sub Operation()

  56:              Console.WriteLine("ConcreteImplementorB Operation")

  57:          End Sub

  58:      End Class