將代碼錯誤從VB6轉換爲vb.net

Question

嘗試將讀卡器從VB6改編爲vb.net。轉換後，我得到這個錯誤：

'AddressOf' expression cannot be converted to 'Integer' because 'Integer' is not a delegate type 

這裏是我使用的代碼：

Public Sub SetupCallBacks() 
    'UPGRADE_WARNING: Add a delegate for AddressOf OnEventDeviceStateChanged Click for more: 'ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?keyword="E9E157F7-EF0C-4016-87B7-7D7FBBC6EE08"' 
    Call MTUSCRADeviceStateChangedNotify(AddressOf OnEventDeviceStateChanged) 
    'UPGRADE_WARNING: Add a delegate for AddressOf OnEventCardDataStateChanged Click for more: 'ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?keyword="E9E157F7-EF0C-4016-87B7-7D7FBBC6EE08"' 
    Call MTUSCRACardDataStateChangedNotify(AddressOf OnEventCardDataStateChanged) 
End Sub 


Public Sub OnEventDeviceStateChanged(ByVal parm As Integer) 
    If (gbEvents) Then 
     If (glDeviceState <> parm) Then 
      glDeviceState = parm 
     End If 

     Select Case glDeviceState 
      Case MTSCRA_STATE_DISCONNECTED 
       SetStatus(("OnEventDeviceStateChanged:Disconnected")) 
      Case MTSCRA_STATE_CONNECTED 
       SetStatus(("OnEventDeviceStateChanged:Connected")) 
      Case MTSCRA_STATE_ERROR 
       SetStatus(("OnEventDeviceStateChanged:Error")) 
     End Select 
    End If 
End Sub 

據我知道我需要做什麼代表，但我不知道如何去做吧。

Answer 1

你需要聲明一個代理，像這樣：

Delegate Sub DeviceStateChangedDelegate(ByVal param As Integer) 

然後SetupCallBacks方法，你需要創建並調用您的委託，像這樣的內部：

Public Sub SetupCallBacks() 
    ' Declare and instantiate the delegate 
    Dim MTUSCRADeviceStateChangedNotify As DeviceStateChangedDelegate 
    MTUSCRADeviceStateChangedNotify = AddressOf OnEventDeviceStateChanged 

    ' Invoke the delegate, passing it 10, which is obviously made up 
    MTUSCRADeviceStateChangedNotify.Invoke(10) 
End Sub