Tuesday 12/20/2010

Option Strict On
Imports System
Namespace InterfaceDemo
'define the interface
Interface IStorable
Sub Read()
Sub Write(ByVal obj As Object)
Property Status() As Integer
End Interface

'create a class that implements the IStorable interface

Public Class document
Implements IStorable
'oh cool it just added a bunch of things on its own

Private myStatus As Integer = 0

Public Sub New(ByVal s As String)
Console.WriteLine("Creaing document with: {0}", s)
End Sub 'new

Public Sub Read() Implements IStorable.Read
Console.WriteLine("Implementing the Read Method for IStorable")
End Sub 'read

Public Property Status As Integer Implements IStorable.Status
Get
Return myStatus
End Get
Set(ByVal value As Integer)
myStatus = value
End Set
End Property

Public Sub Write(ByVal obj As Object) Implements IStorable.Write
Console.WriteLine("Implementing the write method for IStorable.")
End Sub 'write
End Class

Class tester
Public Sub run()
Console.writeline("Implementing Tester.Run")


Dim doc As New document("Test Document")
doc.status = -1
doc.read()
console.writeline("Document status: {0} ", doc.status)
End Sub
End Class

End Namespace

Module Module1

Sub Main()
Dim t As New InterfaceDemo.tester()
t.run()
Console.WriteLine("Ran an instance of InterfaceDemo.tester()")
Console.ReadLine()
End Sub

End Module

Classes can implement any number of interfaces.

Option Strict On
Imports System
Namespace InterfaceDemo
Interface IStorable
Sub Read()
Sub Write(ByVal obj As Object)
Property status() As Integer
End Interface 'IStorable

Interface ICompressible
Sub Compress()
Sub Decompress()
End Interface 'ICompressible

'document implements both interfaces

Public Class Document
Implements ICompressible, IStorable

'hold the value for IStorable's Status property
Private myStatus As Integer = 0

'the document constructor
Public Sub New(ByVal s As String)
Console.WriteLine("Creating document with {0} ", s)
End Sub 'New



Public Sub Compress() Implements ICompressible.Compress
Console.WriteLine("Implementing Compress")
End Sub

Public Sub Decompress() Implements ICompressible.Decompress
Console.WriteLine("Implementing Decompress")
End Sub

Public Sub Read() Implements IStorable.Read
Console.WriteLine("Implementing the read method for IStorable")
End Sub 'Read

Public Property status As Integer Implements IStorable.status
Get
Return myStatus
End Get
Set(ByVal value As Integer)
myStatus = value
End Set
End Property

Public Sub Write(ByVal obj As Object) Implements IStorable.Write
Console.WriteLine("Implementing the Write Method for IStorable")
End Sub 'Write
End Class


End Namespace

And here is a variation I wrote:

Class Tester
Public Sub Run(ByVal textValue As String)
Dim doc As New Document(textValue)
doc.status = -1
doc.Read()
doc.Compress()
Console.WriteLine("Document Status: {0}", doc.status)
End Sub 'Run
End Class

End Namespace

Module Module1
Sub Main()
Dim textVal As String = ""
For i = 1 To 5
textVal = "Document #" & i.ToString
Dim t As New InterfaceDemo.Tester()
t.Run(textVal)
Next

Console.ReadLine()

End Sub 'main
End Module