using System;
using System.Threading;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        private Boolean _bStartThread;
        private Int64 _total;

        public Form1()
        {
            InitializeComponent();
            Control.CheckForIllegalCrossThreadCalls = false;
            _bStartThread = false;
            _total = 0;
        }

        private void Run()
        {
            if (!_bStartThread)
            {
                _bStartThread = true;
                Thread thread = new Thread(new ThreadStart(ThreadFun));
                thread.IsBackground = true;
                thread.Start();
            }
        }

        private void ThreadFun()
        {
            while (_bStartThread)
            {
                Interlocked.Increment(ref _total);
                this.Text = _total.ToString();
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Run();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            _bStartThread = false;
        }
    }
}