在VB.net中的代码中创建串行端口

Question

我试图只使用代码在VB.net中创建一个串口.因为我正在创建一个类库,所以我无法使用内置组件.我试过实例化一个新的SeialPort()对象,但这似乎还不够.我确信有一些简单的东西我很想念,任何帮助都会非常感激!谢谢!

PS我应该补充一点,我此时遇到的问题是获取处理datareceived事件的代码.除此之外它可能正在起作用,但由于这个问题我无法分辨.

Answer 1

如果要使用事件,请确保使用'withevents'声明serialPort对象.下面的示例将允许您连接到串行端口,并将使用接收的字符串引发事件.

Imports System.Threading

Imports System.IO

Imports System.Text

Imports System.IO.Ports


Public Class clsBarcodeScanner

Public Event ScanDataRecieved(ByVal data As String)
WithEvents comPort As SerialPort

Public Sub Connect()
    Try
        comPort = My.Computer.Ports.OpenSerialPort("COM5", 9600)
    Catch
    End Try
End Sub

Public Sub Disconnect()

    If comPort IsNot Nothing AndAlso comPort.IsOpen Then
        comPort.Close()
    End If

End Sub

Private Sub comPort_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles comPort.DataReceived
    Dim str As String = ""
    If e.EventType = SerialData.Chars Then
        Do
            Dim bytecount As Integer = comPort.BytesToRead

            If bytecount = 0 Then
                Exit Do
            End If
            Dim byteBuffer(bytecount) As Byte


            comPort.Read(byteBuffer, 0, bytecount)
            str = str & System.Text.Encoding.ASCII.GetString(byteBuffer, 0, 1)

        Loop
    End If

    RaiseEvent ScanDataRecieved(str)

End Sub
End Class