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.