串行端口数据仅在设置断点时有效

debugcn 发表于 Dev

技术先生

我有一个程序，该程序启动超声波风速计，然后在5秒钟后请求读数。当我在“数据接收”处理程序中放置一个断点时，从风量计返回的数据将得到正确处理，但是，如果我没有适当的断点，则该数据将被忽略。代码如下（在键盘上按F2键时将调用startWG）


    Dim WGCom As New SerialPort
    Private Function initWG() As Boolean

        Dim WGPort = My.Settings.WGCom
        If Not (WGCom.IsOpen) Then
            Try
                WGCom.PortName = "COM" & WGPort
                WGCom.Parity = Parity.Even
                WGCom.DataBits = 7
                WGCom.StopBits = StopBits.One
                WGCom.Handshake = Handshake.None
                'WGCom.ReadTimeout = 3000
                WGCom.WriteTimeout = 50000
                WGCom.Open()

            Catch ex As InvalidOperationException
                MessageBox.Show(ex.Message)

            Catch ex As UnauthorizedAccessException
                MessageBox.Show(ex.Message)

            Catch ex As System.IO.IOException
                MessageBox.Show(ex.Message)

            End Try
        End If

        If (WGCom.IsOpen) Then
            Return True
        Else
            Return False
        End If
    End Function
#If (WGPort > 0) Then

#End If
    'What to do with the wind gauge data when it is received.
    Public Sub DataReceivedHandler(
                        sender As Object,
                        e As SerialDataReceivedEventArgs)

        Dim sp As SerialPort = CType(sender, SerialPort)
        Dim indata As String = sp.ReadExisting()
        'MsgBox("Seen Data from WG " & indata)
        If (indata.Length  0) Then
                reading = indata.Substring(plus - 1, 5)
                read = True
            End If
        Catch ex As Exception

        End Try
        Try
            minus = InStr(indata, "-")
            If (minus > 0) Then
                reading = indata.Substring(minus - 1, 5)
                read = True
            End If
        Catch ex As Exception

        End Try

        If (read) Then
            WGReading = reading
            ' MsgBox(reading)
            WGHasRead = True
            read = False
            plus = 0
            minus = 0
            Dim forClass As New WGReads
            forClass.Reading = reading
            SerialLog.WGReadings.Add(forClass)
            RaiseEvent PropertyChanged("DataReceivedHandler", New PropertyChangedEventArgs("LastWG"))
            WGFill(wgfield, hjevent)
        End If

    End Sub

    Public Sub WGStart(wg() As String, hjevents As hjCompetition)
        wgfield = wg
        hjevent = hjevents
        If (initWG()) Then
            AddHandler WGCom.DataReceived, AddressOf DataReceivedHandler

            Dim initBuffer(9) As Byte
            initBuffer(0) = &H1
            initBuffer(1) = &H13
            initBuffer(2) = &H43
            initBuffer(3) = &H57
            initBuffer(4) = &H49
            initBuffer(5) = &H2
            initBuffer(6) = &H30
            initBuffer(7) = &H35
            initBuffer(8) = &H4
            Try
                WGCom.Write(initBuffer, 0, initBuffer.Length)
            Catch ex As System.TimeoutException
            End Try
            'After init wait for the wind gauge to catch up
            System.Threading.Thread.Sleep(100)
            Dim outputBuffer1(9) As Byte
            outputBuffer1(0) = &H1
            outputBuffer1(1) = &H13
            outputBuffer1(2) = &H43
            outputBuffer1(3) = &H57
            outputBuffer1(4) = &H53
            outputBuffer1(5) = &H2
            outputBuffer1(6) = &H30
            outputBuffer1(7) = &H30
            outputBuffer1(8) = &H4
            Try
                WGCom.Write(outputBuffer1, 0, outputBuffer1.Length)
            Catch ex As System.TimeoutException
            End Try
            'Wait for the wind gauge to finish
            wait(5500)

            'Add a handler for when data is received from the Wind Gauge
            AddHandler WGCom.DataReceived, AddressOf DataReceivedHandler

            'Get the reading from the wind gauge
            Dim getBuffer(9) As Byte
            getBuffer(0) = &H1
            getBuffer(1) = &H13
            getBuffer(2) = &H43
            getBuffer(3) = &H57
            getBuffer(4) = &H4F
            getBuffer(5) = &H2
            getBuffer(6) = &H30
            getBuffer(7) = &H30
            getBuffer(8) = &H4
            Try
                WGCom.Write(getBuffer, 0, getBuffer.Length)

            Catch ex As System.TimeoutException
            End Try
            'closeCom()

        End If
    End Sub

数据接收处理程序中的断点在哪里都没有关系，但是只要有一个。如果断点在WGStart Sub中，则它也不起作用。

断点肯定不会改变程序的执行方式吗？

在此先感谢您的帮助。

技术先生

添加wait（100）解决了该问题。对于其他正在寻找类似问题的解决方案的人，wait子代码如下

Private Sub wait(ByVal interval As Integer)
   Dim sw As New Stopwatch
      sw.Start()
      Do While sw.ElapsedMilliseconds < interval
      ' Allows UI to remain responsive
        Application.DoEvents()
      Loop
   sw.Stop() 
End Sub

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