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 &nb
补充：软件开发 , Vb ,
