internal sealed class DataArrivedEventArgs : EventArgs
    {
        private readonly Int32 data;

        public DataArrivedEventArgs(Int32 data)
        {
            this.data = data;
        }

        public Int32 Data 
        {
            get { return data; }
        }
    }

    internal sealed class MyComponent
    {
        private const Int32 dueTime = 5000;
        private readonly Timer timer;
        private readonly Random random;

        public MyComponent()
        {
            this.timer = new Timer(TimerElapsed, null, dueTime, Timeout.Infinite);
            this.random = new Random();
        }

        private void TimerElapsed(Object state)
        {
            OnDataArrived(new DataArrivedEventArgs(random.Next()));
        }

        private void OnDataArrived(DataArrivedEventArgs args)
        {
            var handler = DataArrived;
            if (handler != null)
            {
                DataArrived(this, args);
            }
            timer.Change(dueTime, Timeout.Infinite);
        }

        public event EventHandler<DataArrivedEventArgs> DataArrived;
    }

    public partial class Form1 : Form
    {
        private readonly MyComponent component;
        private readonly SynchronizationContext context;

        public Form1()
        {
            InitializeComponent();

            this.context = SynchronizationContext.Current;
            this.component = new MyComponent();
            this.component.DataArrived += new EventHandler<DataArrivedEventArgs>(DataArrived);
        }

        private void DataArrived(Object sender, DataArrivedEventArgs args)
        {
            context.Send(_ => textBox1.Text = args.Data.ToString(), null);
        }
    }