Question

我又回来了，代码比上次多了。我可以在这里和那里参考我以前的问题，但这个问题是独立的

我设法说服我的雇主放弃我使用的专有串口通信库，所以现在我从头开始使用SerialPorts和BackgroundWorkers，以便我知道它们是如何工作的。

这是我的代码：

Imports System
Imports System.IO.Ports

Public Class Form1

    'SerialPort Port and BackgroundWorker Worker declared in form

    Delegate Sub AppendText_Delegate(ByVal txtBox As TextBox, ByVal str As String)

    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load

        Port.PortName = ("COM9")
        Port.BaudRate = 115200
        Port.Parity = Parity.None
        Port.StopBits = StopBits.One
        Port.Handshake = Handshake.None
        Port.ReadTimeout = 1000
        Port.WriteTimeout = 1000

        Port.Open()

        AddHandler Port.DataReceived, AddressOf DataReceived

        Worker.WorkerReportsProgress = True
        Worker.WorkerSupportsCancellation = True

    End Sub

    Private Sub btnSend_Click(sender As System.Object, e As System.EventArgs) Handles btnSend.Click
        Port.Write(txtInput.Text & vbCrLf)
    End Sub

    Private Sub DataReceived(sender As Object, e As SerialDataReceivedEventArgs)
        Worker.RunWorkerAsync()
    End Sub

    Private Sub BackgroundWorker1_DoWork(sender As System.Object, e As System.ComponentModel.DoWorkEventArgs) Handles Worker.DoWork

        If Worker.CancellationPending Then
            e.Cancel = True
        End If
        AppendText_ThreadSafe(Me.txtOutput, Port.ReadLine())

    End Sub

    Private Sub AppendText_ThreadSafe(ByVal txtBox As TextBox, ByVal str As String)
        If txtBox.InvokeRequired Then
            Dim MyDelegate As New AppendText_Delegate(AddressOf AppendText_ThreadSafe)
            Me.Invoke(MyDelegate, New Object() {txtBox, str})
        Else
            txtBox.AppendText(str)
        End If
    End Sub

End Class

此刻我真的不确定DataReceived事件和BackgroundWorker如何协同工作。我应该在哪里放置Worker.RunWorkerAsync()，以便仅在DataReceived事件被引发时调用DoWork（）？我应该将两个事件绑定到同一个方法吗？

感谢您的帮助，并为此问题的简单性道歉。我刚刚开始使用BackgroundWorkers并且仍然可以找到我的立足点。可以这么说。

Answer 1

DataReceived类的SerialPort事件是在后台线程上引发的，因此它不会阻止UI线程，因此您不需要在此使用BackgroundWorker案件。因为在后台线程上调用DataReceived，所以如果需要更新该处理程序中的任何UI控件，则需要使用Invoke。

背景工作者和连续事件

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