Public Class Form2
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        '       Проверка  на заполнение полей
        If TextBox1.Text = "" Then MsgBox("Все  обязательные поля должны быть заполнены", 48, "Сообщение") : Exit Sub

        Таблица_товараTableAdapter1.Insert(TextBox1.Text)

    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Me.DialogResult = Windows.Forms.DialogResult.OK
        Me.Close()
    End Sub
End Class

Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
        Dim searchString As String = TextBox1.Text 'получить строку для поиска
        If Not (searchString = String.Empty) Then
            Dim i As Integer = ListBox1.FindString(searchString)
            If Not (i = -1) Then
                ListBox1.SelectedIndex = i
            Else
                If MsgBox("Такого товара нет в списке!" & vbLf & "Добавить?", vbInformation + vbYesNo + vbDefaultButton2, "Сообщение") = vbYes Then
                    Dim f As New Form2
                    If f.ShowDialog = Windows.Forms.DialogResult.OK Then
                        Me.База_данных9DataSet.таблица_товара.Clear()
                        Me.Таблица_товараTableAdapter.Fill(Me.База_данных9DataSet.таблица_товара)

                    End If

                    'MessageBox.Show("Строка """ & searchString & """ не найдена", "", MessageBoxButtons.OK, MessageBoxIcon.Information)
                End If
            End If
        End If
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        '       Проверка  на заполнение полей
        If TextBox1.Text = "" Then MsgBox("Все  обязательные поля должны быть заполнены", 48, "Сообщение") : Exit Sub
        Using con As New System.Data.OleDb.OleDbConnection
            con.ConnectionString = My.Settings.База_данных9ConnectionString
            con.Open()
            Using cmd As System.Data.OleDb.OleDbCommand = con.CreateCommand
                cmd.CommandText = "INSERT INTO `таблица товара` (`Наименование товара`) VALUES (@t)"
                cmd.Parameters.AddWithValue("@t", TextBox1.Text)
                cmd.ExecuteNonQuery()
            End Using
        End Using
    End Sub

                  Dim f As New Form2
                    If f.ShowDialog = Windows.Forms.DialogResult.OK Then
                        Me.База_данных9DataSet.таблица_товара.Clear()
                        Me.Таблица_товараTableAdapter.Fill(Me.База_данных9DataSet.таблица_товара)

                    End If

    Private Sub TextBox1_TextChanged(sender As System.Object, e As System.EventArgs) Handles TextBox1.TextChanged
        Dim sSt As String = TextBox1.Text 'получить строку для поиска
        Ds1.таблица_товара.Clear()
        If sSt.Length < 3 Then
            Return
        End If
        Using con As New System.Data.OleDb.OleDbConnection
            con.ConnectionString = conctring
            con.Open()
            Using cmd As System.Data.OleDb.OleDbCommand = con.CreateCommand
                cmd.CommandText = "SELECT *FROM `таблица товара` WHERE InStr(1,`Наименование товара`,@t)>0;"
                cmd.Parameters.AddWithValue("@t", TextBox1.Text)
                Ds1.таблица_товара.Load(cmd.ExecuteReader())
    If Ds1.таблица_товара.rows.count=0 then TextBox2.Text=TextBox1.Text   
            End Using

        End Using

    End Sub