c# visual studio WPF Application Output from MainWindow textbox to Secondary window - visual-studio-2012

Question

Ok, I'm a noob so go easy on me.
I have created an app in WPF using c#.
Of the many functions I have made one is a textbox that shows a countdown from 1:0:0 to 0.
This has a start/reset, play/pause, +30sec, -30 sec buttons attached.
They all work perfectly. However, I need the output showing from that particular textbox to show in a secondary window I have created in either another or duplicated textbox.
Is this even possible?
Thanks
public void CountDownTimer()
{
_timer = new DispatcherTimer(new TimeSpan(0, 0, 1), DispatcherPriority.Normal, delegate
{
// _time = TimeSpan.FromMinutes(60);
ShowTimer.Text = _time.ToString("c");
if (_time == TimeSpan.Zero) _timer.Stop();
_time = _time.Add(TimeSpan.FromSeconds(-1));
}, Application.Current.Dispatcher);
}
//STARTS TIMER FROM 1HOUR ALSO RESETS
private void StartButton_Click(object sender, RoutedEventArgs e)
{
_time = TimeSpan.FromMinutes(60);
_timer.Start();
}
//PAUSES AND COMMENCES TIMER NOTE: THIS DOES NOT RESET THE TIMER
private void PauseButton_Click(object sender, RoutedEventArgs e)
{
if (_timer.IsEnabled)
{
_timer.Stop();
}
else _timer.Start();
}

Answer 1

I know you're aware that there's bad practice here, so I won't chew you out for that. :D
The easiest way to achieve what you want is to have the secondary window as a member of the first window, then change your DispatchTimer's callback to
_timer = new DispatcherTimer(new TimeSpan(0, 0, 1), DispatcherPriority.Normal, delegate
{
// _time = TimeSpan.FromMinutes(60);
ShowTimer.Text = _time.ToString("c");
if (_time == TimeSpan.Zero) _timer.Stop();
_time = _time.Add(TimeSpan.FromSeconds(-1));
secondaryWindow.TextBoxTimer = _time;
}, Application.Current.Dispatcher);
It depends on where and how you instantiate your secondary window, and if the first window has reference to it. You might also consider raising an event when the timer changes, and subscribing the secondary window to that event with a handler that updates the textbox. Better yet, don't use controls like TextBox as a variable, but bind them to a property in another class. That's a step towards MVVM.