前端之家收集整理的这篇文章主要介绍了
VB.NET 串口异步访问,
前端之家小编觉得挺不错的,现在分享给大家,也给大家做个参考。
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,-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,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,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