Testing whether a key on keyboard is actually pressed

With a textbox, button, and timer control set with an interval of 5000 msec:

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

 

namespace ButtonHitTest

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

 

        private void textBox1_KeyPress(object sender, KeyPressEventArgs e)

        {

            if (!Char.IsDigit(e.KeyChar))

                e.Handled = true;

            else

                timer1.Enabled = true;

        }

 

        private void timer1_Tick(object sender, EventArgs e)

        {

            if (!String.IsNullOrEmpty(textBox1.Text))

                MessageBox.Show("There is something in the box");

 

            timer1.Enabled = false;

        }

    }

}