Per lanciare uno thread come backgroundworker

using System.Threading;
using System.ComponentModel;

1) nel form designer, aggiungere il backGroundWorker fa i controlli

2) nel form.design.cs, aggiungere di netto una cosa del tipo 
         // 
         // bgWorkerMuovi
         // 
         this.bgWorkerMuovi.WorkerReportsProgress = true;
         this.bgWorkerMuovi.WorkerSupportsCancellation = true;
         this.bgWorkerMuovi.DoWork += new System.ComponentModel.DoWorkEventHandler(this.bgWorkerMuovi_DoWork);
         this.bgWorkerMuovi.ProgressChanged += new System.ComponentModel.ProgressChangedEventHandler(this.bgWorkerMuovi_ProgressChanged);
         this.bgWorkerMuovi.RunWorkerCompleted += new System.ComponentModel.RunWorkerCompletedEventHandler(this.bgWorkerMuovi_RunWorkerCompleted);

3) nel form.cs aggiungere la chiamata e i tre delegati, es
 chiamata:
      private void btnStart_Click(object sender, EventArgs e)
      {
         int arg =  = Convert.ToInt32(cbVel.SelectedItem);
         try
         {  bgWorkerMuovi.RunWorkerAsync(arg);
            Trace.WriteLine("Inizio ...");
         }
         catch(Exception ex)
         {  MessageBox.Show("[BGMuovi] "+ex.Message);
         }
      }
	  
 fermata:
      private void btnStop_Click(object sender, EventArgs e)
      {  bgWorkerMuovi.CancelAsync();
         statusStripLabel.Text = "Task cancellato";
      }
	  

delegati:

      private void bgWorkerMuovi_DoWork(object sender, DoWorkEventArgs e)
      {  int arg;

         BackgroundWorker worker = sender as BackgroundWorker;
         arg = (int) e.Argument;

         GeneraPunto GP = new GeneraPunto(worker,context,e);

         GP.Genera(arg);
      }

      private void bgWorkerMuovi_ProgressChanged(object sender, ProgressChangedEventArgs e)
      {  //progressBar1.Value = e.ProgressPercentage;
         statusStripLabel.Text = (string)e.UserState;
            //
            // fire an event in this class to notify other classes
            //
      }

      private void bgWorkerMuovi_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
      {  string msg;

         if (e.Cancelled)           // The user canceled the operation.
            msg = String.Format("Operazione annullata dall'utente");
         else if (e.Error != null)  // There was an error during the operation.
            msg = String.Format("Errore: {0}", e.Error.Message);
         else                       // The operation completed normally.
         {  msg = String.Format("Risultato = {0}", e.Result);
         }

         statusStripLabel.Text = msg;
         MessageBox.Show(msg);
      }

Nel codice da lanciare:

   class GeneraPunto
   {
      public BackgroundWorker BGworker;
      private SynchronizationContext context;
      private DoWorkEventArgs e;

      // Costruttore
      public GeneraPunto(BackgroundWorker worker, SynchronizationContext ctxt, DoWorkEventArgs ea)
      {  BGworker = worker;
         context  = ctxt;
         e        = ea;
      }

in qualunque funzione

         e.Result = "Fatto tutto";

		//report progress
		if(qualche condizione)
		   BGworker.ReportProgress((int)((100.0 / SD.numCol) * idRoute),"Sto costruendo");

		// If operation canceled by the user, set DoWorkEventArgs.Cancel property to true.
		if (BGworker.CancellationPending)
		{  e.Cancel = true;
		   return;
		}