Code listing for Visual Basic tutorial

Imports iAnywhere.Data.UltraLite
Public Class Form1
    Dim Conn As ULConnection
    Dim ids() As Integer
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As 
      System.EventArgs) Handles MyBase.Load
        Try
            Dim ConnString As String = "dbf=\Program Files\VBApp\VBApp.udb"
            Conn = New ULConnection(ConnString)
            Conn.Open()
            Conn.DatabaseID = 1
            RefreshListBox()
        Catch
            MsgBox("Exception: " + Err.Description)
        End Try
    End Sub
    Private Sub RefreshListBox()
        Try
            Dim cmd As ULCommand = Conn.CreateCommand()
            Dim I As Integer = 0
            lbNames.Items.Clear()
            cmd.CommandText = "SELECT ID, Name FROM Names"
            Dim dr As ULDataReader = cmd.ExecuteReader()
            ReDim ids(dr.RowCount)
            While (dr.MoveNext)
                lbNames.Items.Add(dr.GetString(1))
                ids(I) = dr.GetInt32(0)
                I = I + 1
            End While
            dr.Close()
            txtName.Text = " "
        Catch ex As Exception
            MsgBox(ex.ToString)
        End Try
    End Sub

    Private Sub btnInsert_Click(ByVal sender As System.Object, ByVal e As 
      System.EventArgs) Handles btnInsert.Click
        Try
            Dim RowsInserted As Long
            Dim cmd As ULCommand = Conn.CreateCommand()
            cmd.CommandText = "INSERT INTO Names(name) VALUES (?)"
            cmd.Parameters.Add("", txtName.Text)
            RowsInserted = cmd.ExecuteNonQuery()
            cmd.Dispose()
            RefreshListBox()
        Catch
            MsgBox("Exception: " + Err.Description)
        End Try
    End Sub

    Private Sub btnUpdate_Click(ByVal sender As System.Object, ByVal e As 
      System.EventArgs) Handles btnUpdate.Click
        Try
            Dim RowsUpdated As Long
            Dim updateID As Integer = ids(lbNames.SelectedIndex)
            Dim cmd As ULCommand = Conn.CreateCommand()
            cmd.CommandText = "UPDATE Names SET name = ? WHERE id = ?"
            cmd.Parameters.Add("", txtName.Text)
            cmd.Parameters.Add("", updateID)
            RowsUpdated = cmd.ExecuteNonQuery()
            cmd.Dispose()
            RefreshListBox()
        Catch
            MsgBox("Exception: " + Err.Description)
        End Try
    End Sub

    Private Sub btnDelete_Click(ByVal sender As System.Object, ByVal e As 
      System.EventArgs) Handles btnDelete.Click
        Try
            Dim RowsDeleted As Long
            Dim deleteID As Integer = ids(lbNames.SelectedIndex)
            Dim cmd As ULCommand = Conn.CreateCommand()
            cmd.CommandText = "DELETE From Names WHERE id = ?"
            cmd.Parameters.Add("", deleteID)
            RowsDeleted = cmd.ExecuteNonQuery()
            cmd.Dispose()
            RefreshListBox()
        Catch
            MsgBox("Exception: " + Err.Description)
        End Try
    End Sub
End Class