C Sharp: Timer stoppen aus einer anderen Klasse heraus

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;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        // Timer erzeugen
        private Timer timer1 = new Timer();
        private int counter = 0;

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            // Timer starten
            timer1.Enabled = true;
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            counter++;
            label1.Text = counter.ToString();
        }

        private void button2_Click(object sender, EventArgs e)
        {   
            // Ein Objekt der anderen Klasse erzeugen
            classMethoden test = new classMethoden();
            // Das Event abbonieren
            test.stopTimerEvent += new EventHandler(stopMyTimer);
            // Methode aufrufen die anschließend das Event triggert
            test.doSomething();
        }

        //Eventhandler der den Timer stoppt
        private void stopMyTimer(object sender,EventArgs e)
        {
            timer1.Enabled = false;
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            timer1.Enabled = false;
            timer1.Tick += new EventHandler(timer1_Tick);
            timer1.Interval = 100;
        }

    }
}

public class classMethoden
{
    public event EventHandler stopTimerEvent;
    public void doSomething()
    {
        // Hier was machen , am Ende wird die Event-Procedure getriggert
        execute_event();
    }
    public void execute_event()
    {
        // Event triggern
        if (stopTimerEvent != null)
            stopTimerEvent(this, new EventArgs());
    }
}