title: Ensure statement is executed only once when a key is pressed and held.
body: <p>If you press and hold the 5 key on the numpad it will continue to execute a statement in the KeyDown event handler. How can i ensure the statement is executed only once, even if i hold the key down?</p>
  
  <p>Thanks for your attention.          </p>
  
  <pre><code>private void form_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e)
  {
     if (e.KeyCode == Keys.NumPad5)
     {
          dados.enviar("f"); //I want this to run only once!
     }
  }
  </code></pre>