VB.Net/Class/Interface

Class implements two interfaces

Imports System
Public Class MainClass
    
    Shared Sub Main()
        Dim doc As New Document("Test Document")
        doc.Status = -1
        doc.Read(  )
        doc.rupress(  )
        Console.WriteLine("Document Status: {0}", doc.Status)
    End Sub
End Class
     Interface IStorable
         Sub Read(  )
         Sub Write(ByVal obj As Object)
         Property Status(  ) As Integer
     End Interface
     Interface ICompressible
         Sub Compress(  )
         Sub Decompress(  )
     End Interface
     Public Class Document
         Implements ICompressible, IStorable
         Public Sub New(ByVal s As String)
             Console.WriteLine("Creating document with: {0}", s)
         End Sub
         Public Sub Read(  ) Implements IStorable.Read
             Console.WriteLine("Implementing the Read Method for IStorable")
         End Sub
         Public Sub Write(ByVal o As Object) Implements IStorable.Write
             Console.WriteLine( _
               "Implementing the Write Method for IStorable")
         End Sub
         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 Compress(  ) Implements ICompressible.rupress
             Console.WriteLine("Implementing Compress")
         End Sub
         Public Sub Decompress(  ) Implements ICompressible.Decompress
             Console.WriteLine("Implementing Decompress")
         End Sub
         Private myStatus As Integer = 0
     End Class

Define and use Interface

Imports System
Public Class MainClass
    Shared Sub Main(ByVal args As String())
        Dim doc As New Document("Test Document")
             doc.Status = -1
             doc.Read( )
             Console.WriteLine("Document Status: {0}", doc.Status)    
        End Sub
End Class
Interface IStorable
    Sub Read( )
    Sub Write(ByVal obj As Object)
    Property Status( ) As Integer
End Interface "IStorable
Public Class Document
    Implements IStorable
    Public Sub New(ByVal s As String)
        Console.WriteLine("Creating document with: {0}", s)
    End Sub "New
    " implement the Read method
    Public Sub Read( ) Implements IStorable.Read
        Console.WriteLine("Implementing the Read Method for IStorable")
    End Sub "Read
    " implement the Write method
    Public Sub Write(ByVal o As Object) Implements IStorable.Write
        Console.WriteLine( _
           "Implementing the Write Method for IStorable")
    End Sub "Write
    " implement the property
    Public Property Status( ) As Integer Implements IStorable.Status
        Get
            Return myStatus
        End Get
        Set(ByVal Value As Integer)
            myStatus = Value
        End Set
    End Property
    " store the value for the property
    Private myStatus As Integer = 0
End Class "Document

Define and use Interface Age

Imports System
Imports System.Windows.Forms
Imports System.Drawing.Text
Imports System.Drawing
Imports System.Drawing.Drawing2D
Public Class MainClass
    
    Shared Sub Main(ByVal args As String())
      Dim person As New CPerson("A", "B", 1983)
      Dim iAgeArray As IAge() = New IAge(1) {}
      iAgeArray(0) = person
      iAgeArray(1) = New CPerson("C", "D", 1999)
      Console.WriteLine( person.ToString() & ": " & _
         person.Name & vbCrLf & "Age is " & person.Age )
      Dim ageReference As IAge
      For Each ageReference In iAgeArray
         Console.WriteLine( ageReference.Name & ": " & _
            "Age is " & ageReference.Age )
      Next
    End Sub
End Class

Public Interface IAge
   ReadOnly Property Age() As Integer
   ReadOnly Property Name() As String
End Interface
Public Class CPerson
   Implements IAge
   Private mYearBorn As Integer
   Private mFirstName As String
   Private mLastName As String
   Public Sub New(ByVal firstNameValue As String, _
      ByVal lastNameValue As String, _
      ByVal yearBornValue As Integer)
      mFirstName = firstNameValue
      mLastName = lastNameValue
      If (yearBornValue > 0 AndAlso _
         yearBornValue <= Date.Now.Year) Then
         mYearBorn = yearBornValue
      Else
         mYearBorn = Date.Now.Year
      End If
   End Sub
   ReadOnly Property Age() As Integer _
      Implements IAge.Age
      Get
         Return Date.Now.Year - mYearBorn
      End Get
   End Property
   ReadOnly Property Name() As String _
      Implements IAge.Name
      Get
         Return mFirstName & " " & mLastName
      End Get
   End Property
End Class

Generic Class and Interface

Imports System.Collections
Imports System.Collections.Generic
Public Class MainClass
   Public Shared Sub Main()
        Dim aCat As New Talker(Of Cat)(New Cat())
        Dim aDog As New Talker(Of Dog)(New Dog())
        aCat.TalkIt()
        aDog.TalkIt()
   End Sub
End Class
Public Interface ITalker
    Sub Talk()
End Interface
Public Class Talker(Of T As ITalker)
    Dim talkerItem As T
    Public Sub New(ByVal shooterItem As T)
        Me.talkerItem = shooterItem
    End Sub
    Public Sub TalkIt()
        Me.talkerItem.Talk()
    End Sub

End Class

Public Class Dog
    Implements ITalker
    Public Sub Talk() Implements ITalker.Talk
        Console.Out.WriteLine("Dog->Talk")
    End Sub
End Class
Public Class Cat
    Implements ITalker
    Public Sub Talk() Implements ITalker.Talk
        Console.Out.WriteLine("Cat->Talk")
    End Sub
End Class

Implement an Interface

Imports System
Imports System.Collections

Public Class MainClass
  Shared Sub Main()
    Dim e1 As New Programmer("E1", 50000)
    Dim e2 As New Employee("E2", 40000)
    
    Dim theTeam As Employee() = {e1, e2}
    
    e1.MyTeam = theTeam
    
    Console.WriteLine(e1.Rate(e2))
    
  End Sub
End Class

Public Interface ILead
  Sub SpendMoraleFund(ByVal amount As Decimal)
  Function Rate(ByVal aPerson As Employee) As String
  Property MyTeam() As Employee()
  Property MoraleFund() As Decimal
End Interface
Public Class Programmer
  Inherits Employee
  Implements ILead
  Private m_MoraleFund As Decimal
  Private m_MyTeam As Employee()
  Public Function Rate(ByVal aPerson As Employee) As String _
  Implements ILead.Rate
    Return aPerson.TheName & " rating to be done"
  End Function
  Public Property MyTeam() As Employee() _
  Implements ILead.MyTeam
    Get
      Return m_MyTeam
    End Get
    Set(ByVal Value As Employee())
      m_MyTeam = Value
    End Set
  End Property
  Public Sub SpendMoraleFund(ByVal amount As Decimal) _
  Implements ILead.SpendMoraleFund
    "spend some money
    Console.WriteLine("Spent " & amount.ToString())
  End Sub
  Public Property OurMoraleFund() As Decimal Implements ILead.MoraleFund
    Get
      Return m_MoraleFund
    End Get
    Set(ByVal Value As Decimal)
      m_MoraleFund = Value
    End Set
  End Property
  Public Sub New(ByVal theName As String, ByVal curSalary As Decimal)
    MyBase.New(theName, curSalary)
  End Sub
End Class
Public Class Employee
  Private m_Name As String
  Private m_Salary As Decimal
  Public Sub New(ByVal theName As String, ByVal curSalary As Decimal)
    m_Name = theName
    m_Salary = curSalary
  End Sub
  Public ReadOnly Property TheName() As String
    Get
      Return m_Name
    End Get
  End Property
  Public ReadOnly Property Salary() As Decimal
    Get
      Return MyClass.m_Salary
    End Get
  End Property
End Class

Implements an Interface

Imports System
Public Class MainClass
    
    Shared Sub Main()
        Dim doc As New Document("Test Document")
        doc.Status = -1
        doc.Read()
        Console.WriteLine("Document Status: {0}", doc.Status)
    End Sub
End Class
     Interface IStorable
         Sub Read()
         Sub Write(ByVal obj As Object)
         Property Status() As Integer
     End Interface "IStorable
     Public Class Document
         Implements IStorable
         Public Sub New(ByVal s As String)
             Console.WriteLine("Creating document with: {0}", s)
         End Sub
         Public Sub Read() Implements IStorable.Read
             Console.WriteLine("Implementing the Read Method for IStorable")
         End Sub
         Public Sub Write(ByVal o As Object) Implements IStorable.Write
             Console.WriteLine( _
                "Implementing the Write Method for IStorable")
         End Sub
         Public Property Status() As Integer Implements IStorable.Status
             Get
                 Return myStatus
             End Get
             Set(ByVal Value As Integer)
                 myStatus = Value
             End Set
         End Property
         Private myStatus As Integer = 0
     End Class "Document

Implements Two Interfaces

Imports System
Public Class MainClass
    Shared Sub Main(ByVal args As String())
        Dim doc As New Document("Test Document")
        doc.Status = -1
        doc.Read( )
        doc.rupress( )
        Console.WriteLine("Document Status: {0}", doc.Status)
    End Sub
End Class
Interface IStorable
    Sub Read( )
    Sub Write(ByVal obj As Object)
    Property Status( ) As Integer
End Interface "IStorable
" here"s the new interface
Interface ICompressible
    Sub Compress( )
    Sub Decompress( )
End Interface "ICompressible
" Document implements both interfaces
Public Class Document
    Implements ICompressible, IStorable
    " the document constructor
    Public Sub New(ByVal s As String)
        Console.WriteLine("Creating document with: {0}", s)
    End Sub "New
    " implement IStorable
    Public Sub Read( ) Implements IStorable.Read
        Console.WriteLine("Implementing the Read Method for IStorable")
    End Sub "Read
    Public Sub Write(ByVal o As Object) Implements IStorable.Write
        Console.WriteLine( _
          "Implementing the Write Method for IStorable")
    End Sub "Write
    Public Property Status( ) As Integer Implements IStorable.Status
        Get
            Return myStatus
        End Get
        Set(ByVal Value As Integer)
            myStatus = Value
        End Set
    End Property
    " implement ICompressible
    Public Sub Compress( ) Implements ICompressible.rupress
        Console.WriteLine("Implementing Compress")
    End Sub "Compress
    Public Sub Decompress( ) Implements ICompressible.Decompress
        Console.WriteLine("Implementing Decompress")
    End Sub "Decompress
    Private myStatus As Integer = 0
End Class

Interface Inherits another Interface

Imports System
Public Class MainClass
    Shared Sub Main(ByVal args As String())
             Dim doc As New Document("Test Document")
             If TypeOf doc Is IStorable Then
                 Dim isDoc As IStorable = doc
                 isDoc.Read( )
             Else
                 Console.WriteLine("Could not cast to IStorable")
             End If
             If TypeOf doc Is ICompressible2 Then
                 Dim ilDoc As ICompressible2 = doc
                 Console.Write("Calling both ICompressible and ")
                 Console.WriteLine("ICompressible2 methods...")
                 ilDoc.rupress( )
                 ilDoc.LogSavedBytes( )
             Else
                 Console.WriteLine("Could not cast to ICompressible2")
             End If
             If TypeOf doc Is ICompressible Then
                 Dim icDoc As ICompressible = doc "
                 Console.WriteLine( _
                    "Treating the object as Compressible... ")
                 icDoc.rupress( )
             Else
                 Console.WriteLine("Could not cast to ICompressible")
             End If
    End Sub
End Class

     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
     Interface ICompressible2
         Inherits ICompressible
     Sub LogSavedBytes( )
    End Interface "ICompressible2
    Public Class Document
         Implements ICompressible2, IStorable
         
         Public Sub New(s As String)
            Console.WriteLine("Creating 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 Sub Write(ByVal o As Object) Implements IStorable.Write
             Console.WriteLine("Implementing the Write Method for IStorable")
         End Sub "Write
         Public Property Status( ) As Integer Implements IStorable.Status
             Get
                 Return myStatus
             End Get
             Set(ByVal Value As Integer)
                 myStatus = Value
             End Set
         End Property
         " implement ICompressible
         Public Sub Compress( ) Implements ICompressible.rupress
             Console.WriteLine("Implementing Compress")
         End Sub "Compress
         Public Sub Decompress( ) Implements ICompressible.Decompress
             Console.WriteLine("Implementing Decompress")
         End Sub "Decompress
         " implement ICompressible2
         Public Sub LogSavedBytes( ) Implements ICompressible2.LogSavedBytes
             Console.WriteLine("Implementing LogSavedBytes")
         End Sub "LogSavedBytes
         " hold the data for IStorable"s Status property
         Private myStatus As Integer = 0
     End Class "Document

Interface inherits interface

Imports System
Public Class MainClass
    
    Shared Sub Main()
        Dim doc As New Document("Test Document")
        If TypeOf doc Is IStorable Then
            Dim isDoc As IStorable = doc
            isDoc.Read()
        Else
            Console.WriteLine("Could not cast to IStorable")
        End If
        If TypeOf doc Is ICompressible2 Then
            Dim ilDoc As ICompressible2 = doc
            Console.Write("Calling both ICompressible and ")
            Console.WriteLine("ICompressible2 methods...")
            ilDoc.rupress()
            ilDoc.LogSavedBytes()
        Else
            Console.WriteLine("Could not cast to ICompressible2")
        End If
        If TypeOf doc Is ICompressible Then
            Dim icDoc As ICompressible = doc
            Console.WriteLine( _
               "Treating the object as Compressible... ")
            icDoc.rupress()
        Else
            Console.WriteLine("Could not cast to ICompressible")
        End If
    End Sub
End Class

     Interface IStorable
         Sub Read()
         Sub Write(ByVal obj As Object)
         Property Status() As Integer
     End Interface
     Interface ICompressible
         Sub Compress()
         Sub Decompress()
     End Interface
     Interface ICompressible2
         Inherits ICompressible
         Sub LogSavedBytes()
     End Interface 
     Public Class Document
         Implements ICompressible2, IStorable
         Public Sub New(s As String)
             Console.WriteLine("Creating document with: {0}", s)
         End Sub
         Public Sub Read() Implements IStorable.Read
             Console.WriteLine("Implementing the Read Method for IStorable")
         End Sub
         Public Sub Write(ByVal o As Object) Implements IStorable.Write
             Console.WriteLine( _
                   "Implementing the Write Method for IStorable")
         End Sub
         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 Compress() Implements ICompressible.rupress
             Console.WriteLine("Implementing Compress")
         End Sub
         Public Sub Decompress() Implements ICompressible.Decompress
             Console.WriteLine("Implementing Decompress")
         End Sub
         Public Sub LogSavedBytes() Implements ICompressible2.LogSavedBytes
             Console.WriteLine("Implementing LogSavedBytes")
         End Sub
         Private myStatus As Integer = 0
     End Class

One Class implements two Interfaces which have the same name method

Imports System
Imports System.Data
Imports System.Collections
public class MainClass
   Shared Sub Main()
        Dim c As New Class1()
        Dim i2 As MySecondInterface
        c.rumonFunction()
        i2 = c
        i2.rumonFunction()
   End Sub
End Class

Interface MyFirstInterface
    Sub UniqueFunction()
    Sub CommonFunction()
End Interface
Interface MySecondInterface
    Sub SecondUniqueFunction()
    Sub CommonFunction()
End Interface
Public Class Class1
    Implements MyFirstInterface
    Implements MySecondInterface
    Sub UniqueFunction() Implements MyFirstInterface.UniqueFunction
    End Sub
    Sub SecondUniqueFunction() Implements MySecondInterface.SecondUniqueFunction
    End Sub
    Sub CommonFunction() Implements MyFirstInterface.rumonFunction
        Console.WriteLine("Common Function on first interface")
    End Sub
    Sub CommonFunctionSecondInterface() Implements MySecondInterface.rumonFunction
        Console.WriteLine("Common function on second interface")
    End Sub
End Class