using System;
using System.Windows.Forms;
using System.Drawing;
using System.Threading;

public class Test
{
        static void Main ()
        {
                TestForm form = new TestForm ();
                Application.Run (form);
        }
}

public class TestForm : Form
{
        public TestForm ()
        {
                Button button = new Button ();
                button.Parent = this;
                button.Location = new Point (5, 5);
                button.Text = "Click me";
                button.Click += OnButtonClick;
        }

        void OnButtonClick (object o, EventArgs args)
        {
                Graphics graphics = CreateGraphics ();
                Point point = new Point (0, 0);
                string str = "User click.";

                graphics.DrawString (str, Font, new SolidBrush (ForeColor),
                                point);
                Thread.Sleep (1000 * 10); // This allows the text to appear in the form
                graphics.FillRectangle (new SolidBrush (BackColor),
                                new RectangleF (point, graphics.MeasureString (str, Font))); // 'Clean' form
                graphics.Dispose ();
        }
}