private bool IsNumber(Key key)
{
bool result = key == Key.D1 || key == Key.D2 || key == Key.D3
|| key == Key.D4 || key == Key.D5 || key == Key.D6
|| key == Key.D7 || key == Key.D8 || key == Key.D9 || key == Key.D0
|| key == Key.NumPad1 || key == Key.NumPad2 || key == Key.NumPad3
|| key == Key.NumPad4 || key == Key.NumPad5 || key == Key.NumPad6
|| key == Key.NumPad7 || key == Key.NumPad8 || key == Key.NumPad9 || key == Key.NumPad0
|| key == Key.Decimal || key == Key.OemPeriod || key == Key.Tab || key == Key.Subtract
|| key == Key.OemMinus;
return result;
}