BackgroundWorker et progressBar

http://msdn.microsoft.com/fr-fr/library/system.componentmodel.backgroundworker(v=vs.110).aspx

public BackgroundWorker backgroundWorker1;

        private void button1_Click(object sender, EventArgs e)

        {

            // Using System.ComponentModel;

            // la variable contenant le nombre d'opérations à effectuer

            int operationCount=Convert.ToInt32(textBox1.Text);

            progressBar1.Minimum = 0;

            progressBar1.Step = 1;

            progressBar1.Value = 0;

            progressBar1.Maximum =operationCount ;

            backgroundWorker1 = new BackgroundWorker() { WorkerReportsProgress = true };

            backgroundWorker1.DoWork += new DoWorkEventHandler(this.backgroundWorker1_DoWork);

            backgroundWorker1.ProgressChanged += new ProgressChangedEventHandler(this.backgroundWorker1_ProgressChanged);

            backgroundWorker1.RunWorkerCompleted += new RunWorkerCompletedEventHandler(this.backgroundWorker1_RunWorkerCompleted);

            // on passe la variable en argument

            backgroundWorker1.RunWorkerAsync(operationCount);

        }

        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)

        {

            for (int i = 0; i <= (int)e.Argument; i++)

            {

                Thread.Sleep(500); // pour la démo

                int n = i * 100 / ((int)e.Argument);

                backgroundWorker1.ReportProgress(n);

            }

        }

        private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)

        {

            label1.Text = string.Format("{0} %",e.ProgressPercentage.ToString());

            this.progressBar1.PerformStep();

        }

        private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)

        {

            MessageBox.Show("Fini !!");

        }