vb.net - オブジェクト参照がオブジェクト VB.Net OleDbCommand のインスタンスに設定されていません

Question

データベースを検索するたびに、「オブジェクト参照がオブジェクトのインスタンスに設定されていません」と表示されます。誰か助けてください。ありがとうございました。

検索用のコードは次のとおりです。

Private Sub BtnSearch_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnSearch.Click

    If TBSearch.Text = "" Then
        MsgBox("Please enter keyword to search...", MsgBoxStyle.Information, "Keyword to search...")`
        TBSearch.Focus()
        Exit Sub
    End If
    Call OpenConnection()
    With OleDa
        Call Initialized()
        .SelectCommand = New OleDb.OleDbCommand() <-------- Error appears here.
        .SelectCommand.CommandText = "SELECT * FROM [HighSchool] WHERE [LastName] Like '%%" & TBSearch.Text & "%%' or [FirstName] Like '%%" & TBSearch.Text & "%%' or [MI] Like '%%" & TBSearch.Text & "%%'" & _
        "Or [Gender] Like '%%" & TBSearch.Text & "%%' or [Address] Like '%%" & TBSearch.Text & "%%' or [Birthday] Like '%%" & TBSearch.Text & "%%' or [RNumber] Like '%%" & TBSearch.Text & "%%'" & _
        "Or [ENumber] Like '%%" & TBSearch.Text & "%%'  ORDER By LastName ASC"
        .SelectCommand.Connection = OleCn

        Call PopulateListView()

        If Me.LV.Items.Count >= 1 Then
            MsgBox(Me.LV.Items.Count & " Record(s) found for " & "( " & Me.TBSearch.Text & " )", MsgBoxStyle.OkOnly, "Record(s) found...")
        Else
            MsgBox("No record(s) found for " & "( " & Me.TBSearch.Text & " )" & " , please try again... ", MsgBoxStyle.Critical, "No record found...")
            TBSearch.Focus()
            TBSearch.SelectAll()
        End If
    End With
    Call CloseConnection()
End Sub

Populate ListView のコードは次のとおりです。

Public Sub PopulateListView() Me.LV.Items.Clear() Dim OleDr As OleDb.OleDbDataReader OleDr = OleDa.SelectCommand.ExecuteReader()

    Do While OleDr.Read()
        Dim Item As New ListViewItem
        Item.Text = IIf(OleDr.IsDBNull(0), "", OleDr.Item(0))
        For shtCntr = 1 To OleDr.FieldCount() - 1
            If Not OleDr.IsDBNull(shtCntr) Then
                Item.SubItems.Add(OleDr.Item("FirstName"))
                Item.SubItems.Add(OleDr.Item("LastName"))
                Item.SubItems.Add(OleDr.Item("MI"))
                Item.SubItems.Add(OleDr.Item("Gender"))
                Item.SubItems.Add(OleDr.Item("Address"))
                Item.SubItems.Add(OleDr.Item("Birthday"))
                Item.SubItems.Add(OleDr.Item("RNumber"))
                Item.SubItems.Add(OleDr.Item("ENumber"))
            Else
                Item.SubItems.Add("")
            End If
        Next shtCntr
        Me.LV.Items.Add(Item)
    Loop
End Sub