Set TextBox value based on AutoComplete TextBox selection in C# and VB.Net

Imports System.ComponentModel
Imports System.Data.OleDb
Imports Dapper

Public Class Form3
    Private iService As New ItemService()
    Private bindingSource1 As BindingSource = Nothing
    Private Sub Form3_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        lblcodeproduct.Visible = False
        TextBox1.AutoCompleteMode = AutoCompleteMode.Suggest
        TextBox1.AutoCompleteSource = AutoCompleteSource.CustomSource
        TextBox1.AutoCompleteCustomSource.AddRange(iService.GetByCodeProduct().Select(Function(n) n.CodeProduct).ToArray())
    End Sub
    Private Sub GetItemData2(ByVal iditem As String)
        Dim item = iService.GetByCodeProductOrBarcode(iditem)
        If item IsNot Nothing Then
            If String.Equals(iditem, item.CodeProduct, StringComparison.CurrentCultureIgnoreCase) Then
                TextBox1.Text = item.CodeProduct
            End If
            TextBox2.Text = item.Barcode
        Else
            TextBox2.Clear()
            Return
        End If
    End Sub
    Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
        If _typingTimer Is Nothing Then
            ' WinForms: 
            _typingTimer = New Timer()
            _typingTimer.Interval = 300
            Static recursive As Boolean = False '<<<<<<<<<<<<<<<<<<<<<<<<<
            If recursive Then Exit Sub '<<<<<<<<<<<<<<<<<<<<<<<<<
            recursive = True '<<<<<<<<<<<<<<<<<<<<<<<<<

            If TextBox1.Text = "" Then
                TextBox2.Clear()
                lblcodeproduct.Visible = False
                ErrorProvider1.SetError(TextBox1, "")
                recursive = False '<<<<<<<<<<<<<<<<<<<<<<<<<
            Else
                Try '<<<<<<<<<<<<<<<<<<<<<<<<<
                    bindingSource1 = New BindingSource With {.DataSource = New BindingList(Of Stock)(CType(iService.GetByCodeProductlike(TextBox1.Text), IList(Of Stock)))}

                    If bindingSource1.Count > 0 Then
                        lblcodeproduct.Visible = False
                        ErrorProvider1.SetError(TextBox1, "")
                    Else
                        lblcodeproduct.Visible = True
                    End If
                    ' the following method might change TextBox1
                    '  which results in the .TextChanged event being called again
                    ' the changes mean that second call stops the processing of the .TextChanged event
                    GetItemData2(TextBox1.Text)
                Finally '<<<<<<<<<<<<<<<<<<<<<<<<<
                    recursive = False '<<<<<<<<<<<<<<<<<<<<<<<<<
                End Try
            End If
            AddHandler _typingTimer.Tick, AddressOf handleTypingTimerTimeout
            _typingTimer.Stop() ' Resets the timer
            _typingTimer.Tag = (TryCast(sender, TextBox)).Text ' This should be done with EventArgs
            _typingTimer.Start()
    End Sub
    Private Sub handleTypingTimerTimeout(ByVal sender As Object, ByVal e As EventArgs)
        Dim timer As Timer = TryCast(sender, Timer) ' WinForms
        If timer Is Nothing Then
            Return
        End If
        ' The timer must be stopped! We want to act only once per keystroke.
        timer.Stop()
    End Sub
End Class
Public Class Stock
    Public Property Id() As Integer
    Public Property CodeProduct() As String
    Public Property Barcode() As String
End Class
Public Class ItemService
    Public Function GetOledbConnectionString() As String
        Return "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\TRIAL.accdb;Persist Security Info=False;"
    End Function
    Private ReadOnly _conn As OleDbConnection
    Private _connectionString As String = GetOledbConnectionString()
    Public Sub New()
        _conn = New OleDbConnection(_connectionString)
    End Sub
    Public Function GetByCodeProduct() As IEnumerable(Of Stock)
        Dim sql = "SELECT CodeProduct AS CodeProduct FROM Items"
        Using _conn = New OleDbConnection(GetOledbConnectionString())
            Return _conn.Query(Of Stock)(sql).ToList()
        End Using
    End Function
    Public Function GetByCodeProductlike(ByVal CodeProduct As String) As IEnumerable(Of Stock)
        Dim sql = $"SELECT CodeProduct FROM Items WHERE CodeProduct LIKE '%" & CodeProduct & "%'"
        Using _conn = New OleDbConnection(GetOledbConnectionString())
            Return _conn.Query(Of Stock)(sql).ToList()
        End Using
    End Function
    Public Function GetByCodeProductOrBarcode(ByVal code As String) As Stock
        Dim sql = $"SELECT * FROM Items WHERE CodeProduct = '{code}' or Barcode = '{code}'"
        Using _conn = New OleDbConnection(GetOledbConnectionString())
            Return _conn.Query(Of Stock)(sql).FirstOrDefault()
        End Using
    End Function
End Class 

Below Google Drive link GIF file

RESULT UPDATE CODE

Below Google Drive link Database

sample database