Creating ITF-14 and Interleaved 2 of 5 Barcodes in .NET: A Comprehensive Guide

dotnet new console -n ItfAndI25Demo -f net8.0
cd ItfAndI25Demo
dotnet add package Aspose.BarCode

using System;
using Aspose.BarCode.Generation;

namespace ItfAndI25Demo
{
    class Program
    {
        // Usage:
        // ITF-14  -> dotnet run -- itf14  400638133393  260930
        //            (first arg "itf14", second is GTIN base ≤13 digits; we'll compute the 14th check digit)
        // I-2/5   -> dotnet run -- i25   123456789
        //
        // Output files:
        //   ITF14_<gtin14>.png
        //   I25_<dataEven>.png

        static int Main(string[] args)
        {
            if (args.Length < 2)
            {
                Console.WriteLine("Usage:");
                Console.WriteLine("  ITF-14: dotnet run -- itf14 <gtin_base_≤13_digits> [xPixels=3] [heightMM=22] [marginMM=4]");
                Console.WriteLine("  I-2/5 : dotnet run -- i25   <numeric_data>        [xPixels=3] [heightMM=22] [marginMM=4]");
                return 1;
            }

            var mode = args[0].Trim().ToLowerInvariant();
            int xPixels = args.Length > 2 && int.TryParse(args[2], out var x) ? Math.Max(1, x) : 3;
            float heightMM = args.Length > 3 && float.TryParse(args[3], out var h) ? Math.Max(10f, h) : 22f;
            float marginMM = args.Length > 4 && float.TryParse(args[4], out var m) ? Math.Max(1f, m) : 4f;

            try
            {
                switch (mode)
                {
                    case "itf14":
                        {
                            string gtinBase = args[1].Trim();
                            if (gtinBase.Length > 13 || !IsAllDigits(gtinBase))
                                throw new ArgumentException("For ITF-14, provide a numeric GTIN base (≤13 digits). The 14th check digit will be computed.");

                            // Build full GTIN-14: left-pad to 13 digits, then add Mod-10 check digit
                            string gtin13 = gtinBase.PadLeft(13, '0');
                            char check = CalcGtin14CheckDigit(gtin13);
                            string gtin14 = gtin13 + check;

                            // ITF-14 encodes the 14-digit GTIN
                            using var gen = new BarCodeGenerator(EncodeTypes.ITF14, gtin14);

                            // Print-friendly defaults
                            gen.Parameters.Barcode.XDimension.Pixels = xPixels;  // bar/module thickness
                            gen.Parameters.Barcode.BarHeight.Millimeters = heightMM;
                            gen.Parameters.Barcode.LeftMargin.Millimeters = marginMM;
                            gen.Parameters.Barcode.RightMargin.Millimeters = marginMM;
                            gen.Parameters.Barcode.TopMargin.Millimeters = Math.Max(2f, marginMM / 2f);
                            gen.Parameters.Barcode.BottomMargin.Millimeters = Math.Max(2f, marginMM / 2f);

                            // Optional: show human-readable text below (depends on layout preference)
                            gen.Parameters.Barcode.CodeTextParameters.Location = CodeLocation.Below;
                            gen.Parameters.Barcode.CodeTextParameters.FontSize.Point = 8f;

                            // Save PNG (lossless)
                            string file = $"ITF14_{gtin14}.png";
                            gen.Save(file, BarCodeImageFormat.Png);

                            Console.WriteLine($"✅ ITF-14 saved: {file}");
                            break;
                        }
                    case "i25":
                    case "interleaved2of5":
                    case "interleaved_2_of_5":
                        {
                            string data = args[1].Trim();
                            if (!IsAllDigits(data))
                                throw new ArgumentException("I-2/5 requires numeric data.");

                            // I-2/5 needs an even number of digits; if odd, left-pad with '0'
                            string evenData = data.Length % 2 == 0 ? data : "0" + data;

                            using var gen = new BarCodeGenerator(EncodeTypes.Interleaved2of5, evenData);

                            // Print-friendly defaults
                            gen.Parameters.Barcode.XDimension.Pixels = xPixels;
                            gen.Parameters.Barcode.BarHeight.Millimeters = heightMM;
                            gen.Parameters.Barcode.LeftMargin.Millimeters = marginMM;
                            gen.Parameters.Barcode.RightMargin.Millimeters = marginMM;
                            gen.Parameters.Barcode.TopMargin.Millimeters = Math.Max(2f, marginMM / 2f);
                            gen.Parameters.Barcode.BottomMargin.Millimeters = Math.Max(2f, marginMM / 2f);

                            gen.Parameters.Barcode.CodeTextParameters.Location = CodeLocation.Below;
                            gen.Parameters.Barcode.CodeTextParameters.FontSize.Point = 8f;

                            string file = $"I25_{evenData}.png";
                            gen.Save(file, BarCodeImageFormat.Png);

                            Console.WriteLine($"✅ Interleaved 2 of 5 saved: {file}");
                            break;
                        }
                    default:
                        throw new ArgumentException("First argument must be 'itf14' or 'i25'.");
                }

                return 0;
            }
            catch (Exception ex)
            {
                Console.Error.WriteLine("❌ Error: " + ex.Message);
                return 2;
            }
        }

        // ----------------- Helpers -----------------

        // GTIN-14 check digit (Mod-10). Argument must be the first 13 digits as a string.
        static char CalcGtin14CheckDigit(string first13)
        {
            if (first13 is null || first13.Length != 13 || !IsAllDigits(first13))
                throw new ArgumentException("CalcGtin14CheckDigit expects 13 numeric digits.");

            int sum = 0;
            // Rightmost (position 13) is index 12; multiply alternating by 3 and 1, starting with 3 on the right.
            // From the rightmost toward left: 3,1,3,1,...
            for (int i = 0; i < 13; i++)
            {
                int digit = first13[12 - i] - '0';
                int weight = (i % 2 == 0) ? 3 : 1;
                sum += digit * weight;
            }
            int mod = sum % 10;
            int check = (10 - mod) % 10;
            return (char)('0' + check);
        }

        static bool IsAllDigits(string s)
        {
            if (string.IsNullOrEmpty(s)) return false;
            foreach (char c in s)
                if (c < '0' || c > '9') return false;
            return true;
        }
    }
}

# ITF-14: pass ≤13 digits, we compute the 14th check digit
dotnet run -- itf14 400638133393
# -> ITF14_0400638133393X.png (X = computed check digit)

# Interleaved 2 of 5: any numeric string; we pad a leading 0 if odd length
dotnet run -- i25 123456789
# -> I25_0123456789.png

string gtin13 = gtinBase.PadLeft(13, '0');
char check = CalcGtin14CheckDigit(gtin13);
string gtin14 = gtin13 + check;
using var gen = new BarCodeGenerator(EncodeTypes.ITF14, gtin14);

string evenData = data.Length % 2 == 0 ? data : "0" + data;
using var gen = new BarCodeGenerator(EncodeTypes.Interleaved2of5, evenData);

gen.Parameters.Barcode.XDimension.Pixels = 3;
gen.Parameters.Barcode.BarHeight.Millimeters = 22f;
gen.Parameters.Barcode.LeftMargin.Millimeters = 4f;
gen.Parameters.Barcode.RightMargin.Millimeters = 4f;
gen.Parameters.Barcode.TopMargin.Millimeters = 2f;
gen.Parameters.Barcode.BottomMargin.Millimeters = 2f;
gen.Parameters.Barcode.CodeTextParameters.Location = CodeLocation.Below;
gen.Parameters.Barcode.CodeTextParameters.FontSize.Point = 8f;