BackgroundWorker

Constants.Worker = new BackgroundWorker();

Constants.Worker.WorkerSupportsCancellation = true;

Constants.Worker.DoWork += delegate

    {

        while (!Constants.Worker.CancellationPending)

        {

            Thread.Sleep();

            for (int i = ; i < ProgramStatus.ChannelCount; i++)

            {

                if (ProgramStatus.IsStopped[i])

                {

                    pictureBoxs[i].Image = pictureBoxs[i].ErrorImage;

                }

            }

        }

    };

Constants.Worker.RunWorkerAsync();

Closing += delegate

    {

        Constants.Worker.CancelAsync();

    };