錯誤：'AddressOf'表達式無法轉換爲'Integer'，因爲'Integer'不是委託類型

Question

將VB6代碼升級到VB.NET時遇到了錯誤。在 AddressOf WindowProc

AddressOf表達發生了錯誤不能被轉換爲 '整數'，因爲 '整數' 不是委託類型

我給SetWindowLong聲明爲：

Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA"(
        ByVal hWnd As Integer, 
        ByVal nIndex As Integer, 
        ByVal dwNewLong As Integer) As Integer 

變量：

Dim GWL_WNDPROC As Short = -4 
Dim hWnd As Integer 

代碼WindowProc：

Function WindowProc(ByVal hw As Integer, ByVal uMsg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As Integer 

    Dim x As Integer 
    Dim a As String 
    Dim wp As Short 
    Dim temp As Object 
    Dim ReadBuffer(1000) As Byte 
    'Debug.Print uMsg, wParam, lParam 
    Select Case uMsg 
     Case 1025 
      Debug.Print(VB6.TabLayout(uMsg, wParam, lParam)) 
      Debug.Print(uMsg & " " & wParam & " " & lParam) 

      e_err = WSAGetAsyncError(lParam) 
      e_errstr = GetWSAErrorString(e_err) 

      If e_err <> 0 Then 
       Debug.Print("Error String returned -> " & e_err & " - " & e_errstr) 
       Debug.Print("Terminating....") 
       do_cancel = True 
       'Exit Function 
      End If 
      Select Case lParam 
       Case FD_READ 'lets check for data 
        x = recv(mysock, ReadBuffer(0), 1000, 0) 'try to get some 
        If x > 0 Then 'was there any? 
         'UPGRADE_ISSUE: Constant vbUnicode was not upgraded. Click for more: 'ms-help://MS.VSCC.v90/dv_commoner/local/redirect.htm?keyword="55B59875-9A95-4B71-9D6A-7C294BF7139D"' 
         'default 
         'a = StrConv(System.Text.UnicodeEncoding.Unicode.GetString(ReadBuffer), vbUnicode) 'yep, lets change it to stuff we can understand 
         a = System.Text.UnicodeEncoding.Unicode.GetString(ReadBuffer) 'yep, lets change it to stuff we can understand 

         Debug.Print(a) 
         rtncode = Val(Mid(a, 1, 3)) 
         'Debug.Print "Analysing code " & rtncode & "..." 
         Select Case rtncode 
          Case 354, 250 

           Progress = Progress + 1 

           Debug.Print(">>Progress becomes " & Progress) 
          Case 220 
           Debug.Print("Recieved Greenlight") 
           Green_Light = True 
          Case 221 

           Progress = Progress + 1 

           Debug.Print(">>Progress becomes " & Progress) 
          Case 550, 551, 552, 553, 554, 451, 452, 500 
           Debug.Print("There was some error at the server side") 
           Debug.Print("error code is " & rtncode) 
           do_cancel = True 
         End Select 
        End If 
       Case FD_CONNECT 'did we connect? 
        mysock = wParam 'yep, we did! yayay 
        'Debug.Print WSAGetAsyncError(lParam) & "error code" 
        'Debug.Print mysock & " - Mysocket Value" 

       Case FD_CLOSE 'uh oh. they closed the connection 
        Call closesocket(wp) 'so we need to close 
      End Select 
    End Select 
    'let the msg get through to the form 
    WindowProc = CallWindowProc(lpPrevWndProc, hw, uMsg, wParam, lParam) 
End Function 

是什麼錯誤我得到的原因是什麼？我該如何解決問題？

Answer 1

而不是試圖使用P/Invoke來設置窗口過程，你看你的覆蓋窗體的WndProc方法？重寫期間可能需要更多的工作，但最終會得到更好的代碼。從以前的鏈接舉例：

Protected Overrides Sub WndProc(ByRef m As Message) 
     ' Listen for operating system messages 
     Select Case (m.Msg) 
      ' The WM_ACTIVATEAPP message occurs when the application 
      ' becomes the active application or becomes inactive. 
     Case WM_ACTIVATEAPP 

       ' The WParam value identifies what is occurring. 
       appActive = (m.WParam.ToInt32() <> 0) 

       ' Invalidate to get new text painted. 
       Me.Invalidate() 

     End Select 
     MyBase.WndProc(m) 
    End Sub 

您還可能要在System.Net.Sockets命名空間來尋找您的當前插座碼合適的替代品。

---

我也發現了一篇文章".NET Makes Window Subclassing Easy"，如果，例如，你不擁有你想要的子類的窗口，它可能是有用的。無論如何，雖然各地，這是不推薦的方法之一是嘗試使用SetWindowLong