C#: Windows Forms: Using a BackgroundWorker with a progress bar

gistfile1.cs

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 BackgroundWorker
{
	public partial class Form1 : Form
	{
		public Form1()
		{
			InitializeComponent();
		}

		private void backgroundWorker1_DoWork( object sender, DoWorkEventArgs e )
		{
			
			for ( int i = 0 ; i < 101 ; i++ )
			{

				if ( backgroundWorker1.CancellationPending )
				{
					e.Cancel = true;
					break;
				}

				backgroundWorker1.ReportProgress( i );

				Thread.Sleep( 20 );

			}

			e.Result = 0;

		}

		private void backgroundWorker1_ProgressChanged( object sender, ProgressChangedEventArgs e )
		{

			progressBar1.Value = e.ProgressPercentage;
			label1.Text = e.ProgressPercentage + "% complete";

		}

		private void backgroundWorker1_RunWorkerCompleted( object sender, RunWorkerCompletedEventArgs e )
		{

			if ( e.Cancelled )
			{

				label1.Text = "Operation cancelled";

			}
			else
			{

				label1.Text = "Operation Complete";

			}


			buttonCancel.Enabled = false;
			buttonStart.Enabled = true;

		}

		private void buttonStart_Click( object sender, EventArgs e )
		{

			buttonCancel.Enabled = true;
			buttonStart.Enabled = false;
			backgroundWorker1.RunWorkerAsync();

		}

		private void buttonCancel_Click( object sender, EventArgs e )
		{

			buttonCancel.Enabled = false;
			backgroundWorker1.CancelAsync();

		}
	}
}