Timothy

委派(Delegate)

定義 Method 結構

 

定義

 

'定義委派
Public Delegate Sub sayHello(ByVal thing As String)

 

 

主程式

 

Imports mod08

Module TestHelloWorldDelegate
    Public Sub Main()
        '建構委派
        Dim handler As New sayHello(AddressOf engHelloWorld)
        '呼喚(喚醒)-同步 
        handler.Invoke("eric")       
    End Sub

    '給委派用的程序
    Private Sub engHelloWorld(ByVal s As String)
        System.Console.WriteLine(s + " Hello World!!!")
    End Sub
End Module

 類別層級

主程式 應用程式層級 (Event)

 

Public Class HelloWorld
    'Data field
    Private _msg As String
    '事件
    Public Event myhandler As sayHello
    '屬性
    Public Property Msg() As String
        Get
            Return Me._msg
        End Get
        Set(ByVal value As String)
            Me._msg = value
        End Set
    End Property

    '引發事件的 method
    Public Sub Rasing(ByVal s As String)
        '引發事件->牽涉到應用系統所寫的事件程序(???)
        RaiseEvent myhandler(s)
    End Sub
End Class

Module TestClassEvent

    Public Sub Main()
        '建構物件
        Dim hello As New HelloWorld()
        '建立事件程序
        '管理員建立
        Dim handler As New sayHello(AddressOf HelloWorld)
        '聽物件的事件
        AddHandler hello.myhandler, handler
        '引發
        hello.Rasing("eric")
    End Sub

    '事件程序
    Private Sub HelloWorld(ByVal s As String)
        System.Console.WriteLine(s + " 世界和平!!")
    End Sub
End Module

mod08.rar