C#

using (Graphics gs = this.CreateGraphics())
    {
    using (Brush b = new SolidBrush(Color.Red))
        {
        using (Pen p = new Pen(b))
            {
            gs.DrawRectangle(p, Goal);
            ...
            }
        }
    ...
    }

private void FrmMain_Paint(object sender, PaintEventArgs e)
    {
    using (Brush b = new SolidBrush(Color.Red))
        {
        using (Pen p = new Pen(b))
            {
            e.Graphics.DrawRectangle(p, Goal);
            }
        }
    }

string[] lines = File.ReadAllLines(filePath);
var barcodes = lines.Select(line => {string[] parts = line.Split(','); 
                                     return parts[2]; });

var x = barcodes.GroupBy(b => b);

string[] lines = File.ReadAllLines(@"C:\Users\<user>\Desktop\Test data.txt");
var barcodes = lines.Select(line => {string[] parts = line.Split(',');
return parts[2]; });
var x = barcodes.GroupBy(b => b);

using System;
using System.Collections.Generic;
using System.Windows;
using System.IO;
using System.Linq;

namespace Inventory
{
	/// <summary>
	/// Interaction logic for Window1.xaml
	/// </summary>
	public partial class Window1 : Window
	{
		void button1_Click(object sender, RoutedEventArgs e)
		{
			
			string[] lines = File.ReadAllLines(@"C:\Users\sdadmin\Desktop\Test data.txt");
			var barcodes = lines.Select(line => {string[] parts = line.Split(',');
			                            	return parts[2]; });
			var x = barcodes.GroupBy(b => b);		
		}
		
		public class List
		{
			public string Date{get; set;}
			public string Time{get; set;}
			public string EAN {get; set;}
		}
	}
}

string[] lines = File.ReadAllLines(filePath);
var barcodes = lines.Select(line => {
    string[] parts = line.Split(',');
    return parts[2];
});
var x = barcodes.GroupBy(b => b);
foreach (var y in x)
    {
    Console.WriteLine($"{y.Key} : {y.Count()}");
    }

1578456329781 : 1
1578453697235 : 3
1548795358155 : 1