namespace BackgroundWorkerProgressBarDemo {     public partial class Form1 : Form     {         public Form1()         {             InitializeComponent();             Shown += new EventHandler(Form1_Shown);             // To report progress from the background worker we need to set this property             backgroundWorker1.WorkerReportsProgress = true;             // This event will be raised on the worker thread when the worker starts             backgroundWorker1.DoWork += new DoWorkEventHandler(backgroundWorker1_DoWork);             // This event will be raised when we call ReportProgress             backgroundWorker1.ProgressChanged += new ProgressChangedEventHandler(backgroundWorker1_ProgressChanged);         }         void Form1_Shown(object sender, EventArgs e)         {             // Start the background worker             backgroundWorker1.RunWorkerAsync();         }         // On worker thread so do our thing!         void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)         {             // Your background task goes here             for (int i = 0; i <= 100; i++)             {                 // Report progress to 'UI' thread                 backgroundWorker1.ReportProgress(i);                 // Simulate long task                 System.Threading.Thread.Sleep(100);             }         }         // Back on the 'UI' thread so we can update the progress bar         void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)         {             // The progress percentage is a property of e             progressBar1.Value = e.ProgressPercentage;         }     } }