VB.NET 串口异步访问

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.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
Builder.Clear()
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
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
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
Builder.Clear()
'清除字符串构造器的内容
Dim b As UpdateData = New UpdateData(AddressOf ShowData)
Me.BeginInvoke(b, Buf)
Catch ex As Exception
Err.Clear()
Finally
Listening = False
'我用完了，ui可以关闭串口了。
End Try
End Sub
Private Sub ShowMsg(ByVal buffer() As Byte)
If CheckBoxHex.Checked Then
For Each b As Byte In Buffer
Builder.Append(b.ToString("X2") + " ")
Next
Else
Builder.Append(Encoding.ASCII.GetString(buffer))
End If
Me.TxtGet.AppendText(Builder.ToString())
labelGetCount.Text = "Get:" + ReceiveCount.ToString
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

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