ช่วยดูให้หน่อยคับมันERROR อะคับ Invalid attempt to call MetaData when reader is closed."

Private Sub SearchAutoLotNo()
        Dim ReadId As String = ""
        Dim NewId As Integer = 0
        Dim dtCountLot As New DataTable()
        Dim CountLot As String = ""
        Dim Sql As String = "SELECT  Count_LotNo FROM StorkDLGB ORDER BY Count_LotNo DESC"
        Com = New SqlCommand
        With Conn
            If .State = ConnectionState.Open Then .Close()
            .ConnectionString = strConn
            .Open()
        End With

        With Com
            .CommandType = CommandType.Text
            .CommandText = Sql
            .Connection = Conn
            dr = .ExecuteReader()
            'dr.Read()
            dtCountLot.Load(dr)
            CountLot = dr.Item("Count_LotNo").ToString()
            If CountLot = "" Then
                TextBox1.Text = "01"
            Else
                NewId = CInt(CountLot) + 1
                TextBox1.Text = NewId.ToString("00")
            End If
            'If dr.HasRows Then
            'dtCountLot.Load(dr)
            'CountLot = CountLot + 1
            'TextBox1.Text = CountLot.ToString("00")
            'Else
            'TextBox1.Text = "01"

            '  dr.Read()
            '   ReadId = dr.Item("LotNo").ToString()
            '  NewId = CInt(ReadId) + 1
            ' TextBox1.Text = NewId.ToString("00")
            'Else
            ' TextBox1.Text = "01"

            'End If
        End With
        dr.Close()
        Conn.Close()
    End Sub