VB.Net/Language Basics/Cast — различия между версиями

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Текущая версия на 12:42, 26 мая 2010

Object casting

Imports System
Imports System.Data
Imports System.Collections
public class MainClass
   Shared Sub Main()
  Dim A As String
        Dim myA As New A()
        Dim myB As New B()
        Dim myAReference As A
        Dim myBReference As B
        Dim myIReference As MyInterface
        Console.WriteLine("Same Type Conversion")
        myAReference = myA  
        Console.WriteLine("Base type - implicit")
        myAReference = myB  
        Console.WriteLine("Implemented interface - implicit")
        myIReference = myA   
        
        myA = CType(myIReference, A)
        Try
            myB = CType(myIReference, B)
        Catch e As Exception
            Console.WriteLine(e.Message)
        End Try
        
        
   End Sub
End Class
    Interface MyInterface
        Sub MyInterfaceFunction()
    End Interface
    Class A
        Implements MyInterface
        Protected Overridable Sub MyFunction()
        End Sub
        Public Sub MyPublicFunction()
        End Sub
        Public Sub MyInterfaceFunction() Implements MyInterface.MyInterfaceFunction
        End Sub
    End Class
    Class B
        Inherits A
    End Class