通过 RS232 进行通信的问题 - VB.net dll / Delphi win32 exe

Question

我有一个与我创建的 vb.net dll 通信的 Delphi 程序。 vb.net dll 通过 RS232 连接与 Fluke 示波器进行通信。我创建了一个通过 RS232 正确通信的程序，给了我预期的价值。但是，当我将它打包为 dll 并从我的 Delphi 程序访问 dll 时，我总是收到“1”的值，而不是我期望的值（大多数情况下是 240 左右的值）。

我知道我的 delphi 程序肯定与 dll 正确通信，并且我的 dll 肯定与范围仪表通信。问题只是返回的值！希望我只是在这里做了一些非常愚蠢的事情，但我看不到它，它开始让我发疯！

这是我的 vb.net 代码：

Public Interface IFlukeComm
    Function GetReading(ByVal Command As String, ByVal PortNum As Integer) As String
    Function Test() As String
End Interface

Public Class FComm : Implements IFlukeComm

Private WithEvents moRS232 As Rs232
Dim InvokeRequired As Boolean
Dim TxResult As String

Private Sub OpenCom(ByVal PortNum As Integer)
    Dim sTx As String
    moRS232 = New Rs232()
    Try
        With moRS232
            .Port = PortNum
            .BaudRate = 1200
            .DataBit = 8
            .StopBit = Rs232.DataStopBit.StopBit_1
            .Parity = Rs232.DataParity.Parity_None
            .Timeout = 1500
        End With

        moRS232.Open()

        moRS232.Dtr = True
        moRS232.Rts = True
        moRS232.EnableEvents()

        moRS232.PurgeBuffer(Rs232.PurgeBuffers.TxClear Or Rs232.PurgeBuffers.RXClear)
        sTx = "PC 9600"
        sTx += ControlChars.Cr

        moRS232.Write(sTx)

        moRS232.Close()
    Catch ex As Exception

    End Try

End Sub

Private Sub moRS232_CommEvent(ByVal source As Rs232, ByVal Mask As Rs232.EventMasks)       Handles moRS232.CommEvent
    If (Mask And Rs232.EventMasks.RxChar) > 0 Then
        TxResult = source.InputStreamString
    End If
End Sub

Public Function GetReading(ByVal Command As String, ByVal PortNum As Integer) As String     Implements IFlukeComm.GetReading
    OpenCom(PortNum)

    Threading.Thread.Sleep(500)

    With moRS232
        .Port = PortNum
        .BaudRate = 9600
        .DataBit = 8
        .StopBit = Rs232.DataStopBit.StopBit_1
        .Parity = Rs232.DataParity.Parity_None
        .Timeout = 1500
    End With

    moRS232.Open()

    moRS232.Dtr = True
    moRS232.Rts = True
    moRS232.EnableEvents()

    Command += ControlChars.Cr
    moRS232.Write(Command)

    Threading.Thread.Sleep(500)

    moRS232.Close()

    If TxResult <> "" Then
        'moRS232.Read(10)
        Dim sRead As String = moRS232.InputStreamString
        Return sRead
    Else
        Return "Invalid"
    End If
End Function

Public Function Test() As String Implements IFlukeComm.Test
    Return "Success"
End Function

End Class

这是我的 Delphi 代码：

procedure TfrmLauncher.btnM1UNClick(Sender: TObject);
begin
  ShowMessage(GetMeasurements('QM 11',cmbM1PC.ItemIndex + 1));
end;

function TfrmLauncher.GetMeasurements(strType : string; iPort : Integer) : string;
var
  IFC : IFlukeComm;
begin
  IFC := CreateComObject(CLASS_FComm) as IFlukeComm;
  Result := IFC.GetReading(strType,iPort);
end;

Answer 1

TxResult = source.InputStreamString

Dim sRead As String = moRS232.InputStreamString

我不使用 VB.net，但看起来您可能正在尝试读取接收缓冲区两次。 InputStreamString 是否允许这样做，还是在读取时为空？