My post earlier today referred to the FileHelpers library by Marcos Meli.

Wow, do I wish I had known about this earlier. This thing is great! With a few easy attributes, you can use a business object as a layout for fixed-length files! Okay, I guess an example would help. Here’s some VB code I whipped up to test this library out.

Imports FileHelpers

Public Class MainForm
  Private Sub MainForm_Load(ByVal sender As Object, _
    ByVal e As System.EventArgs) Handles Me.Load

    Dim engine As New FileHelperEngine(GetType(Record))

    Dim records() As Record = _
      DirectCast(engine.ReadString("123456789 2005-01-01"), _
      Record())

    Debugger.Break()

    Dim res As String = engine.WriteString(records)

    Debugger.Break()
  End Sub
End Class

<FixedLengthRecord()> _
Public Class Record
  <FieldFixedLength(11)> _
  Public BillNumber As String

  <FieldFixedLength(10), _
  FieldConverter(ConverterKind.Date, "yyyy-MM-dd")> _
  Public BillDate As DateTime
End Class

At each Debugger.Break line, I checked my values and this thing is great. records(0).BillNumber is 123456789 and records(0).BillDate is a converted DateTime set to 1/1/2005.

If you deal with fixed-length or delimited files on a regular basis, this library might be a great option for you.

Thanks Marcos!

UPDATE: Version 1.3.1 was released recently, so I have updated my example code to use the new ReadString and WriteString methods.