VB.NET 串口访问之二

新的程序如下。

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Imports System 

Imports System.Collections.Generic 

Imports System.ComponentModel 

Imports System.Data 

Imports System.Drawing 

Imports System.Linq 

Imports System.Text 

Imports System.IO.Ports 

Imports System.Threading 

Imports System.Text.RegularExpressions 

Public Class Form1 

    WithEvents Comm As SerialPort = New SerialPort 

    Private Builder As StringBuilder = New StringBuilder '避免在事件处理方法中反复的创建，所以定义到外面 

    Private ReceiveCount As Long = 0     '接收计数 

    Private SendCount As Long = 0        '发送计数 

    Private Listening As Boolean = False  '是否没有执行完invoke相关操作  

    Private Closingg As Boolean = False     '是否正在关闭串口，执行Application.DoEvents，并阻止再次invoke    

    Public Delegate Sub UpdateData(ByVal mByte() As Byte) 

    Public Sub ShowData(ByVal mByte() As Byte) 

        Console.WriteLine(mByte) 

        ReceiveCount += mByte.Length          '统计字节总数 

        Builder.Clear()                       '清除字符串构造器的内容  

        Console.WriteLine("Main1() invoke on thread{0}.", Thread.CurrentThread.ManagedThreadId) 

        If CheckBoxHex.Checked Then 

            For Each b As Byte In mByte 

                Builder.Append(b.ToString("X2") + " ") 

            Next 

        Else 

            Builder.Append(Encoding.ASCII.GetString(mByte)) 

        End If 

        TxtGet.AppendText(Builder.ToString) 

        labelGetCount.Text = "Get:" + ReceiveCount.ToString 

    End Sub 

    '************************************************************** 

    '委派子程序 

    '处理上述通信端口的接收事件 

    '由于欲将数据显示到接收文字框中，因此必须检查是否由另外的Thread 

    '所呼叫的，若是，则必须先建立委派对象 

    'Invoke用于在拥有控制项基础视窗控制代码的执行绪上执行委派 

    '************************************************************** 

    Private Sub DisplayText(ByVal comData() As Byte) 

        '如果呼叫txtReceive的是另外的执行绪，传回True 

        Try 

            If Me.TxtGet.InvokeRequired Then 

                '利用委派型别建立委派对象，并指定委派的函数 

                Dim d As New UpdateData(AddressOf ShowData) 

                '用大括号{} 括住初始值，藉以初始化阵列的值。 

                Me.Invoke(d, New Object() {comData})  '以指定的引数清单叫用函数 

            Else  '相同的执行绪 

                ShowData(comData)   '将收到的数据填入接收文字框中 

            End If 

        Catch ex As Exception 

            MsgBox(ex.ToString) 

        Finally 

        End Try 

    End Sub 

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

        '初始化下拉串口名称列表框 

        Dim Ports() As String = SerialPort.GetPortNames 

        Array.Sort(Ports) 

        ComboPortName.Items.AddRange(Ports) 

        ComboPortName.SelectedIndex = IIf(ComboPortName.Items.Count > 0, 0, -1) 

        ComboBaudrate.SelectedIndex = ComboBaudrate.Items.IndexOf("9600") 

        '初始化Serialport对象 

        Comm.NewLine = vbCrLf 

        Comm.RtsEnable = True 

        'AddHandler Obj.Ev_Event, AddressOf EventHandler 

        'RemoveHandler Obj.Ev_Event, AddressOf EventHandler 

        'AddHandler Comm.DataReceived, AddressOf Comm_DataReceived 

        BtnXReset.PerformClick() 

    End Sub 

    Private Sub Comm_DataReceived(sender As Object, e As System.IO.Ports.SerialDataReceivedEventArgs) Handles Comm.DataReceived 

        If Closingg Then Return '如果正在关闭，忽略操作，直接返回，尽快的完成串口监听线程的一次循环    

        Try 

            Listening = True                    '设置标记，说明我已经开始处理数据，一会儿要使用系统UI的。 

            Dim n As Long = Comm.BytesToRead    '先记录下来，避免某种原因，人为的原因，操作几次之间时间长，缓存不一致    

            Dim Buf(n - 1) As Byte              '声明一个临时数组存储当前来的串口数据  

            Comm.Read(Buf, 0, n)                '读取缓冲数据 

            Console.WriteLine("Main0() invoke on thread{0}.", Thread.CurrentThread.ManagedThreadId) 

            DisplayText(Buf) 

            'Dim b As UpdateData = AddressOf ShowData 

            'b(Buf)   '同步线程之间传递数据时，必须考虑textbox不在同一线程 

        Catch ex As Exception 

            MsgBox(ex.Message) 

        Finally 

            Listening = False                    '我用完了，ui可以关闭串口了。 

        End Try 

    End Sub 

    Private Sub BtnXOpen_Click(sender As System.Object, e As System.EventArgs) Handles BtnXOpen.Click 

        '根据当前串口对象，来判断操作  

        If Comm.IsOpen Then 

            Closingg = True ' 

            While Listening 

                Application.DoEvents() 

            End While 

            '打开时点击，则关闭串口 

            Comm.Close() 

            Closingg = False 

        Else 

            Comm.PortName = ComboPortName.Text 

            Comm.BaudRate = Integer.Parse(ComboBaudrate.Text) 

            Try 

                Comm.Open() 

            Catch ex As Exception 

                '捕获到异常信息，创建一个新的comm对象，之前的不能用了。  

                Comm = New SerialPort 

                '现实异常信息给客户。  

                MessageBox.Show(ex.Message) 

            End Try 

        End If 

        '设置按钮的状态    

        BtnXOpen.Text = IIf(Comm.IsOpen, "Close", "Open") 

        BtnXOpen.Enabled = Comm.IsOpen 

    End Sub 

    '动态的修改获取文本框是否支持自动换行。  

    Private Sub CheckBoxNewLineGet_CheckedChanged(sender As System.Object, e As System.EventArgs) Handles CheckBoxNewLineGet.CheckedChanged 

        TxtGet.WordWrap = CheckBoxNewLineGet.Checked 

    End Sub 

    Private Sub BtnXSend_Click(sender As System.Object, e As System.EventArgs) Handles BtnXSend.Click 

        Dim n As Integer = 0  '定义一个变量，记录发送了几个字节  

        If checkBoxHexSend.Checked Then   '16进制发送  

            '我们不管规则了。如果写错了一些，我们允许的，只用正则得到有效的十六进制数    

            Dim Mc As MatchCollection = Regex.Matches(TxtSend.Text.Trim, "(?i)[/da-f]{2}")   '"(?i)[/da-f]{2}" 

            Dim buf As List(Of Byte) = New List(Of Byte) 

            '依次添加到列表中    

            For Each m As Match In Mc 

                '  buf.Add(Byte.Parse(m.Value)) 

                buf.Add(Byte.Parse(m.Value, System.Globalization.NumberStyles.HexNumber)) 

            Next 

            '转换列表为数组后发送   

            Comm.Write(buf.ToArray, 0, buf.Count) 

            n = buf.Count 

        Else                             'ascii编码直接发送  

            '包含换行符 

            If checkBoxNewlineSend.Checked Then 

                Comm.WriteLine(TxtSend.Text) 

                n = TxtSend.Text.Length + 2 

            Else 

                Comm.Write(TxtSend.Text) 

                n = TxtSend.Text.Length 

            End If 

        End If 

        SendCount += n    '累加发送字节数  

        labelSendCount.Text = "Send:" + SendCount.ToString 

    End Sub 

    Private Sub BtnXReset_Click(sender As System.Object, e As System.EventArgs) Handles BtnXReset.Click 

        '复位接受和发送的字节数计数器并更新界面。 

        SendCount = 0 

        ReceiveCount = 0 

        labelGetCount.Text = "Get:0" 

        labelSendCount.Text = "Send:0" 

        Builder.Clear() 

    End Sub 

    Private Sub BtxClear_Click(sender As System.Object, e As System.EventArgs) Handles BtxClear.Click 

        TxtGet.Text = "" 

        Builder.Clear() 

    End Sub 

End Class 

摘自：wl58796351的专栏