private void CanExecuteSpeak(object sender, CanExecuteRoutedEventArgs e)
{
DigitalClcok digital = (DigitalClcok)sender;
if (digital.Time != null)
{
e.CanExecute = true;
}
else
{
e.CanExecute = false;
}
}
private void ExecuteSpeak(object sender, ExecutedRoutedEventArgs e)
{
DigitalClcok digital = (DigitalClcok)sender;
digital.SpeakTheTime(digital.Time);
}