using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Runtime.Serialization.Formatters.Binary;
using System.IO;

using Microsoft.VisualStudio.TestTools.UnitTesting;
using System.Runtime.InteropServices;

/**
 * CharSet defined as Ansi
 * Use CharSet.Unicode for scandinavian chars,
 * Unicode might fuck up byte sizes
*/
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
public struct Struct1
{
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 4)]
    public char[] voucher_type;

    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 2)]
    public char[] trans_type;

    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 3)]
    public char[] currency;

    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 4)]
    public char[] cur_amount;

    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 4)]
    public char[] amount;

    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 3)]
    public char[] apar_type;

    public void Write(BinaryWriter writer, byte[] newline)
    {
        var sz = Marshal.SizeOf(this);
        IntPtr pStruct = Marshal.AllocHGlobal(sz);

        Marshal.StructureToPtr(this, pStruct, false);
        var buffer = Array.CreateInstance(typeof(byte), sz) as byte[];
        Marshal.Copy(pStruct, buffer, 0, buffer.Length);

        writer.Write(buffer);
        writer.Write(newline);

        Marshal.Release(pStruct);
    }

    public static Struct1 Read(BinaryReader reader)
    {
        var sz = Marshal.SizeOf(typeof(Struct1));
        var buffer = reader.ReadBytes(sz);

        GCHandle handle = GCHandle.Alloc(buffer, GCHandleType.Pinned);

        Struct1 result = (Struct1)
                Marshal.PtrToStructure(
                handle.AddrOfPinnedObject(),
                typeof(Struct1));

        handle.Free();
        return result;
    }
}


class Foo {

    public static void simple(string fileName) {

        byte[] newline = Encoding.ASCII.GetBytes(Environment.NewLine);

        List<Struct1> expected = new List<Struct1>();

        expected.Add(new Struct1() {
                voucher_type = "0142".ToCharArray(),
                trans_type = "AR".ToCharArray(),
                currency = "NOK".ToCharArray(),
                cur_amount = "9999".ToCharArray(),
                amount = "9999".ToCharArray(),
                apar_type = "001".ToCharArray(),
        });

        expected.Add(new Struct1() {
                voucher_type = "0142".ToCharArray(),
                trans_type = "GL".ToCharArray(),
                currency = "NOK".ToCharArray(),
                cur_amount = "9999".ToCharArray(),
                amount = "9999".ToCharArray(),
                apar_type = "001".ToCharArray(),
        });


        using (FileStream fs = File.Open(fileName, FileMode.Create, FileAccess.Write, FileShare.None))
        {
            var writer = new BinaryWriter(fs);
            foreach (var item in expected)
            {
                item.Write(writer, newline);
            }
        }

    }

    static void Main(string[] args)
    {
        simple("tralala.txt");
    }
}

/* PRODUCES
0142ARNOK99999999001
0142GLNOK99999999001

*/