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我正在为 .net dll 使用 microsoft POS，并且我正在将这部分转换为 vb.net，该部分来自用 c# 编写的 HOL 示例条码阅读教程，可在此处找到。

编辑：设备列表显示和弹出窗口显示（按下激活按钮并测试扫描仪输入）但即使使用扫描仪模拟器，txteventhistory 也不会更新，我怀疑上述部分是罪魁祸首。感谢您的答复

{
        Action<string> updateEventHistoryAction = new Action<string>(p => { txtEventHistory.Text = p; });
        txtEventHistory.Invoke(updateEventHistoryAction, newEvent);
    }

由此

void activeScanner_DataEvent(object sender, DataEventArgs e)
{
UpdateEventHistory("Data Event");
ASCIIEncoding encoder = new ASCIIEncoding();
try
{
    // Display the ASCII encoded label text
    string data = encoder.GetString(activeScanner.ScanDataLabel);
    Action<string> updateScanDataLabelAction = new Action<string>(p => {txtScanDataLabel.Text = p;});
    txtScanDataLabel.Invoke(updateScanDataLabelAction, data);

    // Display the encoding type
    string dataType = activeScanner.ScanDataType.ToString();
    Action<string> updateScanDataTypeLabelAction = new Action<string>(p => { txtScanDataType.Text = p; });
    txtScanDataType.Invoke(updateScanDataTypeLabelAction, dataType);

    // re-enable the data event for subsequent scans
    activeScanner.DataEventEnabled = true;
}
catch (PosControlException)
{
    // Log any errors
    UpdateEventHistory("DataEvent Operation Failed");
}
}

#develop 中的转换工具产生了下面的转换工具，但我认为它不正确

Dim updateScanDataLabelAction As New Action(Of String)(function (p)
                    txtScanDataLabel.Text = p
end function)
txtEventHistory.Invoke(updateEventHistoryAction, newEvent)

我尝试将其转换为但我认为不完全在那里，尽管它

Private Sub activeScanner_DataEvent(sender As Object, e As DataEventArgs)
    UpdateEventHistory("Data Event")
       Dim encoder As New ASCIIEncoding()
          Try
        ' Display the ASCII encoded label text
        Dim data As String = encoder.GetString(activeScanner.ScanDataLabel)
            Dim updateScanDataLabelAction append As New Action(Of String))
               txtEventHistory.Invoke(updateEventHistoryAction, newEvent)
               txtScanDataType.Invoke(updateScanDataTypeLabelAction, dataType)

        ' re-enable the data event for subsequent scans
        activeScanner.DataEventEnabled = True
    Catch generatedExceptionName As PosControlException
            ' Log any errors
            UpdateEventHistory("DataEvent Operation Failed")
      End Try
    End Sub

Private Sub p(ByVal text As String)
            txtScanDataType.Text = text
    End Sub

这是整个代码

Imports Microsoft.PointOfService
Imports System.Collections
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Data
Imports System.Drawing
Imports System.Text
Imports System.Windows.Forms

Namespace POS
    Partial Public Class ScannerLab
        Inherits Form
        Private explorer As PosExplorer
        Private scannerList As DeviceCollection
        Private scannerList1 As DeviceCollection
        Private activeScanner As Scanner

    Public Sub New()
        InitializeComponent()
    End Sub

    Private Sub ScannerLab_Load(ByVal sender As Object, ByVal e As EventArgs)handles mybase.load
        explorer = New PosExplorer()

        scannerList1 = explorer.GetDevices()
        bsdevices.DataSource = scannerList1
        cboDevices.DisplayMember = scannerList1.ToString()

        scannerList = explorer.GetDevices(DeviceType.Scanner)
        devicesBindingSource.DataSource = scannerList
        lstDevices.DisplayMember = scannerList.ToString()
    End Sub

    Private Sub btnActivateDevice_Click(ByVal sender As Object, ByVal e As EventArgs) handles btnActivateDevice.Click
        If lstDevices.SelectedItem IsNot Nothing Then
            ActivateScanner(DirectCast(lstDevices.SelectedItem, DeviceInfo))
        End If
    End Sub

    Private Sub reportFailure()
        Throw New Exception("The method or operation is not implemented.")
    End Sub

    Private Sub ActivateScanner(ByVal selectedScanner As DeviceInfo) 
        'Verifify that the selectedScanner is not null
        ' and that it is not the same scanner already selected
        If selectedScanner IsNot Nothing AndAlso Not selectedScanner.IsDeviceInfoOf(activeScanner) Then
            ' Configure the new scanner
            DeactivateScanner()

            ' Activate the new scanner
            UpdateEventHistory(String.Format("Activate Scanner: {0}", selectedScanner.ServiceObjectName))
            Try
                activeScanner = DirectCast(explorer.CreateInstance(selectedScanner), Scanner)
                activeScanner.Open()
                activeScanner.Claim(1000)
                activeScanner.DeviceEnabled = True
                AddHandler activeScanner.DataEvent, AddressOf activeScanner_DataEvent
                AddHandler activeScanner.ErrorEvent, AddressOf activeScanner_ErrorEvent
                activeScanner.DecodeData = True
                activeScanner.DataEventEnabled = True
            Catch generatedExceptionName As PosControlException
                ' Log error and set the active scanner to none
                UpdateEventHistory(String.Format("Activation Failed: {0}", selectedScanner.ServiceObjectName))
                activeScanner = Nothing
            End Try
        End If
    End Sub

    Private Sub DeactivateScanner()
        If activeScanner IsNot Nothing Then
            ' We have an active scanner, lets log that we are
            ' about to close it.
            UpdateEventHistory("Deactivate Current Scanner")

            Try
                ' Close the active scanner
                activeScanner.Close()
            Catch generatedExceptionName As PosControlException
                ' Log any error that happens
                UpdateEventHistory("Close Failed")
            Finally
                ' Don't forget to set activeScanner to null to
                ' indicate that we no longer have an active
                ' scanner configured.
                activeScanner = Nothing
            End Try
        End If
    End Sub

    Private Sub activeScanner_DataEvent(ByVal sender As Object, ByVal e As DataEventArgs)
        UpdateEventHistory("Data Event")
        Dim encoder As New ASCIIEncoding()

        Try
            ' Display the ASCII encoded label text
            Dim data As String = encoder.GetString(activeScanner.ScanDataLabel)
            Dim updateScanDataLabelAction As New Action(Of String)(AddressOf p)
            txtScanDataLabel.Invoke(updateScanDataLabelAction, data)

            ' Display the encoding type
            Dim dataType As String = activeScanner.ScanDataType.ToString()
            Dim updateScanDataTypeLabelAction As New Action(Of String)(AddressOf p)

            txtScanDataType.Invoke(updateScanDataTypeLabelAction, dataType)

            ' re-enable the data event for subsequent scans
            activeScanner.DataEventEnabled = True
        Catch generatedExceptionName As PosControlException
            ' Log any errors
            UpdateEventHistory("DataEvent Operation Failed")
        End Try
    End Sub
    Private Sub p(ByVal text As String)
        txtScanDataType.Text = text

    End Sub
    Private Sub q(ByVal text As String)
        txtScanDataType.Text = text

    End Sub
    Private Sub UpdateEventHistory(ByVal newEvent As String)
        If txtEventHistory.InvokeRequired Then
            Dim updateEventHistoryAction As New Action(Of String)(AddressOf q)


            txtEventHistory.Invoke(updateEventHistoryAction, newEvent)
        Else
            txtEventHistory.Text = (Convert.ToString(newEvent) & System.Environment.NewLine) + txtEventHistory.Text
        End If
    End Sub

    Private Sub activeScanner_ErrorEvent(ByVal sender As Object, ByVal e As DeviceErrorEventArgs)
        UpdateEventHistory("Error Event")

        Try

            ' re-enable the data event for subsequent scans

            activeScanner.DataEventEnabled = True

        Catch generatedExceptionName As PosControlException
            ' Log any errors
            UpdateEventHistory("ErrorEvent Operation Failed")
        End Try
    End Sub

编辑：更新了代码

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