To start using the FileHelpers Library you only need to add a reference in your project to the file: FileHelpers.dll. you can find it in the Release directory of the distribution. Tip: remember to left the FileHelpers.xml file to get Intellisense support.

Next you need to define a class that maps to the record in the source/detination file.
For this example we use a file with this format:

01732Juan Perez 004350011052002 00554Pedro Gomez 123423006022004 00112Ramiro Politti 000000001022000 00924Pablo Ramirez 033213024112002 ...............

So you must write this class:

C# [FixedLengthRecord()] public class Customer2 { [FieldFixedLength(5)] public int CustId; [FieldFixedLength(20)] [FieldTrim(TrimMode.Right)] public string Name; [FieldFixedLength(8)] [FieldConverter(typeof(TwoDecimalConverter))] public decimal Balance; [FieldFixedLength(8)] [FieldConverter(ConverterKind.Date, "ddMMyyyy")] public DateTime AddedDate; // A custom converter internal class TwoDecimalConverter: ConverterBase { public override object StringToField(string from) { decimal res = Convert.ToDecimal(from); return res / 100; } public override string FieldToString(object from) { decimal d = (decimal) from; return Math.Round(d * 100).ToString(); } } }

VB.NET <FixedLengthRecord()> _ Public Class Customer2 <FieldFixedLength(5)> _ Public CustId As Integer <FieldFixedLength(20), _ FieldTrimAttribute(TrimMode.Right)> _ Public Name As String <FieldFixedLength(8), _ FieldConverter(GetType(TwoDecimalConverter))> _ Public Balance As Decimal <FieldFixedLength(8), _ FieldConverter(ConverterKind.Date, "ddMMyyyy")> _ Public AddedDate As DateTime '-> Custom Converter Friend Class TwoDecimalConverter Inherits ConverterBase Public Overrides Function StringToField(ByVal from As String) As Object Dim res As Decimal = Convert.ToDecimal(from) Return res / 100 End Function Public Overrides Function FieldToString(ByVal from As Object) As String Dim d As Decimal = CType(from, Decimal) Return Math.Round(d * 100).ToString() End Function End Class End Class

Later you need to create a FileHelperEngine and Read/Write files:

C# FileHelperEngine engine = new FileHelperEngine(typeof(Customer)); // To Read Use: Customer[] res = engine.ReadFile("FileIn.txt") as Customer[]; // To Write Use: engine.WriteFile("FileOut.txt", res);

VB.NET Dim engine As New FileHelperEngine(GetType( Customer)) ' To Read Use: Dim res As Customer() = DirectCast(engine.ReadFile("FileIn.txt"), Customer()) ' To Write Use: engine.WriteFile("FileOut.txt", res)

Finally we can use the res array to access each item in the file, for example:

C# foreach (Customer cust in res) { Console.WriteLine("Customer Info:"); Console.WriteLine(cust.Name + " - " + cust.AddedDate.ToString("dd/MM/yy")); }

VB.NET For Each cust As Customer In res) Console.WriteLine("Customer Info:") Console.WriteLine(cust.Name + " - " + _ cust.AddedDate.ToString("dd/MM/yy")) Next