A Look under the hood of the .NET Framework

using System;
using System.Windows.Forms;
using System.Collections.Generic;

namespace UnderTheHoodCSharp.Examples.LambdaExamples
{
	public class InsaneLambdaFactoryRewritten : IButtonFactory
	{
		private int _outerCounter = 1;
		IEnumerable<System.Windows.Forms.Button> IButtonFactory.GenerateButtons()
		{
			InnerClass1 lambda1 = new InnerClass1();
			lambda1.field_this = this;
			List<Button> list = new List<Button>();
			lambda1.counter = 1;
			for (int i = 1; i <= 10; i++)
			{
				InnerClass2 lambda2 = new InnerClass2();
				lambda2.locals = lambda1;
				lambda2.btn = new Button();
				lambda2.btn.Text = _outerCounter.ToString() + " - " + lambda1.counter.ToString();
				lambda2.btn.Click += lambda2.EventHandler;
				list.Add(lambda2.btn);
			}
			return list;
		}

		class InnerClass1
		{
			public int counter;
			public InsaneLambdaFactoryRewritten field_this;
		}

		class InnerClass2
		{
			public InnerClass1 locals;
			public Button btn;

			public void EventHandler(Object sender, EventArgs e)
			{
				locals.counter++;
				if (locals.counter % 10 == 0)
				{
					locals.field_this._outerCounter++;
				}
				btn.Text = locals.field_this._outerCounter.ToString() + " - " + locals.counter.ToString();
			}
		}
	}
}