สอบถามปัญหา VB2010 เชื่อมต่อ MS-Access2010 ทีครับ The ConnectionString property has not been initialized.

Imports System.Data.OleDb
Imports System.Data


Public Class Form1
    Public conn As New OleDbConnection
    Public Sub connectData() Handles MyBase.Load

        Dim connectionString As String = "Provider=Microsoft.ace.OLEDB.12.0;Data Source=.\\twdb.accdb;"

        If conn.State = ConnectionState.Closed Then conn.Open()

    End Sub

    Public Function ExecuteSQL(ByVal prmSQL As String) As Boolean
        connectData()
        Dim addCom As New OleDbCommand
        With addCom
            .CommandType = CommandType.Text
            .CommandText = prmSQL
            .Connection = conn
            .ExecuteNonQuery()

        End With
        ExecuteSQL = True

    End Function
    Public Function ExcuteReader(ByVal prmSQL As String) As OleDbDataReader
        Dim dr As OleDbDataReader
        Dim comm As New OleDbCommand
        connectData()

        With comm
            .CommandType = CommandType.Text
            .CommandText = prmSQL
            .Connection = conn
            dr = .ExecuteReader()
            Return dr

        End With
    End Function

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim dr As OleDbDataReader
        Dim code As String = BS.Text
        Dim s As String = "select * from TGsc where ID_C ='" & code & "' "
        dr = ExcuteReader(s)
        dr.Read()
        LN.Text = dr.Item("Aria").ToString
        SN.Text = dr.Item("Server").ToString
 End Sub