Beginner's Guide to Threading in .NET: Part 2 of n

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;
using System.Threading;

namespace ThreadResumePause_StopUsingEventArgs
{
    public partial class Form1 : Form
    {
        private WorkerThread wt = new WorkerThread();
        private SynchronizationContext context;
        private bool primeThreadCancel = false;


        public Form1()
        {
            InitializeComponent();
            //obtain the current SynchronizationContext
            context = SynchronizationContext.Current;
        }


        void wt_ReportWorkDone(object sender, WorkDoneCancelEventArgs e)
        {

            //+++++++++++++++++++++++++++++++++++++++++++++++++++++
            //NOTE : This would also work to marshal call to UI thread
            //+++++++++++++++++++++++++++++++++++++++++++++++++++++
            
            //this.Invoke(new EventHandler(delegate
            //{
            //    lstItems.Items.Add(e.PrimeFound.ToString());
            //}));


            //marshal call to UI thread
            context.Post(new SendOrPostCallback(delegate(object state)
            {
                this.lstItems.Items.Add(e.PrimeFound.ToString());
            }), null);
    

            //should worker thread be caneclled, has user clicked cancel button?
            e.Cancel = primeThreadCancel;
        }


        private void btnStart_Click(object sender, EventArgs e)
        {
            //start the worker and listen to its ReportWorkDone event
            wt.Start(100000);
            wt.ReportWorkDone += 
                new ReportWorkDoneEventhandler(wt_ReportWorkDone);
            primeThreadCancel= false;
        }

        private void btnCancel_Click(object sender, EventArgs e)
        {
            primeThreadCancel= true;
        }

        private void btnPause_Click(object sender, EventArgs e)
        {
            wt.Pause();
        }

        private void btnResume_Click(object sender, EventArgs e)
        {
            wt.Resume();
        }
    }
}