異步套接字庫不更新形式

Question

我試圖編寫一個小的異步套接字庫，我可以用它來創建客戶端/服務器應用程序。如果我將它放在表單中，我可以讓所有的代碼運行良好，但是如果我嘗試將它移出到它自己的類中，我無法弄清楚如何使用連接狀態更新表單等。下面是代碼，縮短了一點，以便更容易閱讀和輸入。

表格代號：

Class Form1 
Dim Network as NetworkModule 

Public Sub Button1_Click(Sender, e) Handles Button1.Click 
    Network = New NetworkModule("127.0.0.1", 1234) 
End Sub 
End Class 'Form1 

NetworkModule類：

Class NetworkModule 
    Private mSocket as Socket 

    Public Sub New(IP as string, Port as Integer) 
     Dim remoteEP as New IPEndpoint(IP.Parse(IP), Port) 
     mSocket = New Socket(internetwork, stream, tcp) 
     mSocket.BeginConnect(remoteEP, New AsyncCallback(AddressOf onConnect), mSocket) 
     Notify("Connection to " & remoteEP.ToString) 'This one works 
    End Sub 'New 

    Private Sub onConnect(ar as IAsyncResult) 
     mSocket = CType(ar.AsyncState, Socket) 
     mSocket.EndConnect(ar) 
     Notify("Connected") 'This one never shows 
    End Sub 'onConnect 

    Private Delegate Sub _Notify(Msg as String) 
    Private Sub Notify(Msg as String) 
     If Form1.txtLog.InvokeRequired Then 
      Form1.txtLog.Invoke(New _Notify(AddressOf Notify), Msg) 
      Exit Sub 
     End if 
     Form1.txtLog.Text &= Msg & vbcrlf 
    End Sub 'Notify 
End Class 'NetworkModule 

有其實更多的那類，但是第一個消息出去後，我從來沒有得到任何東西。我不確定該從哪裏出發。我嘗試了很多我在谷歌搜索中找到的不同方法，其中一些來自這裏，一些不是。任何人有任何想法？

Answer 1

這是我會怎麼把它改寫：

Class Form1 
    Private Network as NetworkModule 
    Public NotifyDelegate As NetworkModule.NotifyDelegate 

    Public Sub New() 
     NotifyDelegate = New NetworkModule.NotifyDelegate(AddressOf Notify) 
    End Sub 

    Public Sub Button1_Click(Sender, e) Handles Button1.Click 
     Network = New NetworkModule("127.0.0.1", 1234, Me) 
    End Sub 

    Public Sub Notify(Msg As String) 
     txtLog.Text &= Msg & vbCrLf 
    End Sub 
End Class 'Form1 

NetworkModule類（部分）：

Class NetworkModule 
    Public Delegate Sub NotifyDelegate(Msg as String) 

    Private Sub Notify(Msg as String) 
     If m_Form.InvokeRequired Then 
      m_Form.Invoke(Form1.NotifyDelegate, Msg) 
     Else 
      m_Form.Notify(Msg) 
     End If 
    End Sub 'Notify 

    Private mSocket as Socket 

    Private m_Form As Form1 

    Public Sub New(IP as string, Port as Integer, oForm As Form1) 
     m_Form = oForm 
     Dim remoteEP as New IPEndpoint(IP.Parse(IP), Port) 
     mSocket = New Socket(internetwork, stream, tcp) 
     mSocket.BeginConnect(remoteEP, New AsyncCallback(AddressOf onConnect), mSocket) 
     Notify("Connection to " & remoteEP.ToString) 'This one works 
    End Sub 'New 

更新與接口方法

不是通過形式本身是一個更好的機制實現一個接口。爲此，首先創建接口定義（請注意，爲方便起見，代理已移至接口）：

Public Interface INotify 
    Sub Notify(Msg As String) 
    Delegate Sub NotifyDelegate(Msg As String) 
End Interface 

然後在窗體中實現接口。請注意表單現在決定是否需要Invoke。這允許INotify接口用於非UI場景，例如記錄到磁盤或事件日誌。

Public Class Form1 
    Implements INotify 

    Public Sub Notify(Msg As String) 
     txtLog.Text &= Msg & vbCrLf 
    End Sub 

    Private Sub INotify_Notify(Msg As String) Implements INotify.Notify 
     If Me.InvokeRequired Then 
      Me.Invoke(New INotify.NotifyDelegate(AddressOf Notify), Msg) 
     Else 
      Me.Notify(Msg) 
     End If 
    End Sub 'Notify 

    Private Network As NetworkModule 

    Public Sub Button1_Click(Sender, e) Handles Button1.Click 
     Network = New NetworkModule("127.0.0.1", 1234, Me) 
    End Sub 
End Class 'Form1 

最後，存儲到inotify的接口，而不是在NetworkModule形式引用（注意NetworkModule不再需要知道或關心的調用可能需要）：

Public Class NetworkModule 
    Public Delegate Sub NotifyDelegate(Msg As String) 

    Private m_Notifier As INotify 

    Private Sub Notify(Msg As String) 
     m_Notifier.Notify(Msg) 
    End Sub 'Notify 

    Public Sub New(IP As String, Port As Integer, oNotifier As INotify) 
     m_Notifier = oNotifier 
     ' The addition code here 
    End Sub 'New 
End Class