線程問題（我不明白）

Question

互聯網上有很多關於線程的頁面，但是我似乎無法控制它。

我有一個窗體，點擊一個按鈕，循環瀏覽一個文件並逐行讀取它。每行是不同FTP站點的登錄詳細信息。

當它讀取一行時，它將使用登錄詳細信息將一個變量Dim作爲名爲CallFTP的類的新實例。

然後使用名爲PerformFTP的CallFTP中的函數將Dim變量作爲新線程Dim。

PerformFTP返回一個字符串與FTP的結果，我想將它添加到窗體上的一個ListBox開始它的一切。

該按鈕的代碼是這樣......

Private Sub cmdRun_Click(sender As Object, e As EventArgs) Handles cmdRun.Click 
    For Each _FTPLine As String In Split(_FTPDetails, vbNewLine) 
     Dim _Active As Boolean = CBool(Split(_FTPLine, "|")(7)) 

     If _Active Then 
      _CurNum += 1 
      _ID = Format(Now.Year, "0000") & Format(Now.Month, "00") & Format(Now.Day, "00") & Format(Now.Hour, "00") & Format(Now.Minute, "00") & Format(Now.Second, "00") & Format(Now.Millisecond, "000") & Format(_CurNum, "00000") 

      Dim _FTP As New CallFTP(_ID, Split(_FTPLine, "|")(0), Split(_FTPLine, "|")(1), Split(_FTPLine, "|")(2), Split(_FTPLine, "|")(3), Split(_FTPLine, "|")(4), Split(_FTPLine, "|")(5), Split(_FTPLine, "|")(6)) 
      Dim _Thread = New Thread(New ThreadStart(AddressOf _FTP.PerformFTP)) 

      With _Thread 
       .IsBackground = True 
       .Start() 
      End With 
     End If 
    Next _FTPLine 
End Sub 

類是如下（不完全，但你並不需要的代碼的其餘部分笑）

Public Class CallFTP 
    Private _ID As String = "" 
    Private _Response As String = "" 
    Private _IPAddress As String = "" 
    Private _Port As String = "" 
    Private _User As String = "" 
    Private _Pass As String = "" 
    Private _Remote As String = "" 
    Private _Local As String = "" 
    Private _InOut As String = "" 

    Public Sub New(ID As String, Server As String, PortNum As String, Username As String, Password As String, RemoteDir As String, LocalDir As String, InOrOut As String) 
     _ID = ID 
     _IPAddress = Server 
     _Port = PortNum 
     _User = Username 
     _Pass = Password 
     _Remote = RemoteDir 
     _Local = LocalDir 
     _InOut = InOrOut 
    End Sub 

    Public Function PerformFTP() As String 
     Return "This is a test" 
    End Function 
End Class 

任何人都可以解釋我將如何調用一個名爲modMisc的模塊（它向主窗體上的ListBox添加一個字符串）上的子命名LogMessage？

我讀過，你需要調用它，但是我讀的所有東西似乎都讓我頭痛，讓我需要躺在黑暗的房間裏幾個小時。

任何人都可以解釋，就好像你正在說2歲？ :)

任何幫助將不勝感激。

Answer 1

如果要從其創建位置的另一個線程更新它，則需要調用委託來更新GUI。

1º你的委託必須匹配（具有相同的簽名），比方法，你將使用：

Delegate Sub LogMessageExampleDelegate(ByVal x As Integer, ...) 

簽名是指委託必須返回並接收相同類型的比你的函數/方法。

2º使用委託調用您的函數來更新GUI。例如，這您的更新界面函數中：

If yourListBox.InvokeRequired Then 
    yourListBox.Invoke(New LogMessageExampleDelegate(AddressOf THE_FUNCTION_WHICH_UPDATES_THE_GUI_NAME), parameter_value) 
Else 
    'Just call your function 
End If 

利用，爲例如：

sub addToListBox(byval text as string) 
    myListBox.Items.add(text) 
end sub 

所以你的調用將是：

If yourListBox.InvokeRequired Then 
    yourListBox.Invoke(New LogMessageExampleDelegate(AddressOf addToListBox), "Item 1") 
Else 
    'Just call your function 
    addToListBox("Item 1") 
End If 

PS：我寫了這麼希望的兩倍我沒有注意到它，卻沒有搞砸。