從VB5移到VB.NET，並遇到USB .dll調用問題

Question

我試圖與使用FDTI 232RL的USB設備進行通信。我已經安裝了驅動程序，並將.dll調用集成到了我的VB5代碼中，並且運行良好。我想讓這個工作在VB.net上，但我得到了PInvokeStackImballance錯誤消息。在VB5我有下面的代碼序列：

Private Declare Function FT_ListDevices Lib "FTD2XX.DLL" (ByVal arg1 As Long, ByVal arg2 As String, ByVal dwFlags As Long) As Long 
... 
Dim strSerialNumber As String * 256 
... 
LoggerList.AddItem ("ListDevices by S/N") 
If FT_ListDevices(0, strSerialNumber, FT_LIST_BY_INDEX Or FT_OPEN_BY_SERIAL_NUMBER) <> FT_OK Then 
... 

在VB.NET：

Private Declare Function FT_ListDevices Lib "FTD2XX.DLL" (ByVal arg1 As Long, ByVal arg2 As String, ByVal dwFlags As Long) As Long 
... 
Dim strSerialNumber As Stringbuilder new = stringbuilder (" ",256) 
... 
LoggerList.AddItem ("ListDevices by S/N") 
If FT_ListDevices(0, strSerialNumber, FT_LIST_BY_INDEX Or FT_OPEN_BY_SERIAL_NUMBER) <> FT_OK Then 
... 

在if語句出現的錯誤。我是否需要導入帶有導入的Dll（「FTD2XX.dll」）？我也試過Dim strSerialNumber(256) as char，那也不管用。我工作錯了嗎？

Answer 1

在VB5中，一個long是32位，而它在VB.Net中是64位。將函數中的參數從long更改爲int，這是VB.Net上的32位。

Private Declare Function FT_ListDevices Lib "FTD2XX.DLL" (ByVal arg1 As Integer, _ 
     ByVal arg2 As String, ByVal dwFlags As Integer) As Integer