2.vb串口通信技術(shù)文章160rs232串行l(wèi)ooptest的實(shí)例

1、代碼如下：Imports System.IO.PortsImports System.TextPublic Class Form1*窗體的Load 事件中先將所有的通信端口先列出來將通信端口排序，并將第一個(gè)通信端口設(shè)為默認(rèn)值*Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) HandlesMyBase.LoadFor Each sp As String In SerialPort.GetPortNames.Items.Add(sp)Next.Sorted = True 排序.Se

2、lectedIndex = 0 第一個(gè)是默認(rèn)選項(xiàng)End Sub*打開通信端口按鈕的Click 事件此事件將設(shè)定通信端口參數(shù)，并打開通信端口*Private Sub btnOpenPort_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) HandlesbtnOpenPort.ClickDim mPortName As StringmPortName =.SelectedItem.ToString 欲打開的通信端口RS232.PortName = mPortNameRS232.Encoding = Encoding

3、.ASCIIIf Not RS232.IsOpen Then 還未打開RS232.Open() 打開通信端口btnSend.Enabled = True 致能傳送按鈕btnReceive.Enabled = TrueElseMsgBox(通信端口打開錯(cuò)誤(通信端口已被打開), MsgBoxStyle.Critical OrMsgBoxStyle.OkCancel)EndEnd If vb net 源碼和實(shí)例，請關(guān)注(樂 博 網(wǎng))End Sub*傳送按鈕的Click 事件將文字框中的文字以 Write 方法自串行端口送出*Private Sub btnSend_Click(ByVal sende

4、r As System.Object, ByVal e As System.EventArgs) HandlesbtnSend.ClickRS232.Write(txd.Text & vbCr)End Sub*接收按鈕的Click 事件以ReadExisting 方法自串行端口數(shù)據(jù)*Private Sub btnReceive_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) HandlesbtnReceive.ClickDim InString As StringInString = TryRS232.Read

5、Timeout = 1000InString = RS232.ReadExisting()If InString Is Nothing ThenExit SubElsetxtReceive.Text = InStringEnd IfCatch ex As ExceptionMessageBox.Show(錯(cuò)誤： + ex.ToString, 錯(cuò)誤通知, MessageBoxButtons.OK,MessageBoxIcon.Exclamation)End TryEnd Sub*關(guān)閉通信端口按鈕的Click 事件以Cose 方法關(guān)閉通信端口，并對象所占用的資源*Private Sub btnCl

6、ose_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) HandlesbtnClose.ClickIf RS232 Is Nothing OrElse Not RS232.IsOpen Then 還未打開MsgBox(通信端口還未打開, MsgBoxStyle.Critical Or MsgBoxStyle.OkCancel)ElseRS232.Close()btnSend.Enabled = FalsebtnReceive.Enabled = FalseEnd IfEnd Sub*結(jié)束程序按鈕的Click 事件此事件將設(shè)定通信端口參數(shù)，并打開通信端口*Private Sub btnEnd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) HandlesbtnEnd.ClickIf Not RS