C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Threading;

namespace SampleBackgroundWorker
{
  public partial class MainForm : Form
  {
    private BackgroundWorker _worker = new BackgroundWorker();
    private static readonly object SyncLock = new object();
    public MainForm()
    {
      InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
      _worker.WorkerReportsProgress = true;
      _worker.ProgressChanged += new 
        ProgressChangedEventHandler(ProgressChanged);
      _worker.DoWork += new DoWorkEventHandler(DoWork);
      _worker.RunWorkerAsync();
    }

    void DoWork(object sender, DoWorkEventArgs e)
    {
      for (int i = 1; i <= 10; i++)
      {
        lock (SyncLock)
        {
          Monitor.Wait(SyncLock, 1000);
        }
        _worker.ReportProgress(i * 10);
      }
    }

    void ProgressChanged(object sender, ProgressChangedEventArgs e)
    {
      barProgress.Value = e.ProgressPercentage ;
    }
  }
}