VB.NET中的多线程帮助

Question

基本上每隔2秒，我就使用串行连接通过设备获得2位十进制数字的值，因此我已将每个字节转换为字符，然后连接为通过串行端口接收的第二个字符（字节），然后依次分配给一个文本框4（MB， GC，INS，OU），那么每次在MB和OU文本框中（而不是其他文本框中）更新值时，会发生什么情况。 因此，如果有人可以通过这些逻辑帮助我。 （是vb的新手，因此请尽可能地详尽）。

码：

Private Sub SerialPort1_DataReceived(sender As System.Object, e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
    cc = Chr(SerialPort1.ReadByte())
    dd = Chr(SerialPort1.ReadByte())
    ee = cc + dd
    ReceivedText(ee)

End Sub

Private Sub ReceivedText(ByVal [text] As String) 'input from ReadExisting
        If c = 0 Then
        If Me.MB.InvokeRequired Then
            Dim x As New SetTextCallback(AddressOf ReceivedText)
            Me.Invoke(x, New Object() {(text)})
        Else
            Me.MB.Text = [text] 'append text
        End If
            c = 1
        ElseIf c = 1 Then
        If Me.GC.InvokeRequired Then
            Dim x As New SetTextCallback(AddressOf ReceivedText)
            Me.Invoke(x, New Object() {(text)})
        Else
            Me.GC.Text = [text] 'append text
        End If
            c = 2
        ElseIf c = 2 Then
        If Me.OU.InvokeRequired Then
            Dim x As New SetTextCallback(AddressOf ReceivedText)
            Me.Invoke(x, New Object() {(text)})
        Else
            Me.OU.Text = [text] 'append text
        End If
            c = 3
        ElseIf c = 3 Then
        If Me.INS.InvokeRequired Then
            Dim x As New SetTextCallback(AddressOf ReceivedText)
            Me.Invoke(x, New Object() {(text)})
        Else
            Me.INS.Text = [text] 'append text
            c = 0
        End If
    End If
End Sub

Answer 1

如果要设置断点，则会注意到每个调用C被修改了两次。 一个用于“正常”调用，另一个用于调用。 我建议您改变设置“ c”的逻辑。 更改文本框值后将其放置在右边。

Private Sub ReceivedText(ByVal [text] As String) 'input from ReadExisting
    If c = 0 Then
        If Me.MB.InvokeRequired Then
            Dim x As New SetTextCallback(AddressOf ReceivedText)
            Me.Invoke(x, New Object() {(text)})
        Else
            Me.MB.Text = [text] 'append text
            c = 1
        End If

    ElseIf c = 1 Then
        If Me.GC.InvokeRequired Then
            Dim x As New SetTextCallback(AddressOf ReceivedText)
            Me.Invoke(x, New Object() {(text)})
        Else
            Me.GC.Text = [text] 'append text
            c = 2
        End If

    ElseIf c = 2 Then
        If Me.OU.InvokeRequired Then
            Dim x As New SetTextCallback(AddressOf ReceivedText)
            Me.Invoke(x, New Object() {(text)})
        Else
            Me.OU.Text = [text] 'append text
            c = 3
        End If

    ElseIf c = 3 Then
        If Me.INS.InvokeRequired Then
            Dim x As New SetTextCallback(AddressOf ReceivedText)
            Me.Invoke(x, New Object() {(text)})
        Else
            Me.INS.Text = [text] 'append text
            c = 0
        End If
    End If
End Sub

我还建议您放置更多的meaninfull变量名称。 使用c，cc，ee之类的东西没有多大意义。

您也可以减少一些代码。 尽量不要重复自己。 （注意：我没有进行编译以查看它是否有效）。

Private Sub ReceivedText(ByVal [text] As String) 'input from ReadExisting
    Dim tbToUpdate As TextBox

    ' This could even be in an array
    Select Case c
        Case 0
            tbToUpdate = Me.MB
        Case 1
            tbToUpdate = Me.GC
        Case 2
            tbToUpdate = Me.OU
        Case 3
            tbToUpdate = Me.INS
    End Case

    If tbToUpdate.InvokeRequired Then
        Dim x As New SetTextCallback(AddressOf ReceivedText)
        Me.Invoke(x, New Object() {(text)})
    Else
        tbToUpdate.Text = [text] 'append text
        c += 1

        If c == 4 Then
            c = 0
        End If
    End If

End Sub