title: Difference between Keys.Shift and Keys.ShiftKey
body: <p>In my application i detect when a key is pressed and see if the modifier is the shift key but the Keys enumerator has Shift and ShiftKey. </p>
  
  <p>It seems the event is always sending Keys.Shift, but is there a case where the Keys.ShiftKey will be used? </p>
  
  <p>(and the same question applies to Keys.Control and Keys.ControlKey)</p>
  
  <p>Thanks for any input.</p>