Timer in UWP App which isn't linked to the UI

Question

I'm working on an UWP MVVM project and would like to implement an automatic logout system if the user interaction stops for a specific time.
Until now I'm using a DispatcherTimer to count backwards from 200 every second.

TimerLeave = 200;
var _dispatcherTimer = new DispatcherTimer();
_dispatcherTimer.Tick += dispatcherTimer_Tick;
_dispatcherTimer.Interval = new TimeSpan(0, 0, 1);

_dispatcherTimer.Start();

But because the DispatcherTimer is linked with the UI and I'm building a MVVM App, I'm looking for an alternative.
I searched a bit and found Run a background task on a timer. The problem is that this timer can only be set to run every 15 minutes, which is a little too long to automaticly logout a user in my case. I found no workaround to reduce the 15 minutes.
So my question is, is there any possibility to set up a timer in an UWP Project that isn't linked to the UI and can be set variable?

did you check this: [link](http://stackoverflow.com/questions/1416803/system-timers-timer-vs-system-threading-timer) ? — Antonio Ugraal Barile, Dec 14 '15 at 15:51
@AntonioUgraalBarile I totally missed System.Threading.Timer, thank you for this hint. I've only found System.Timer and this one isn't supported in UWP Apps. — croxy, Dec 14 '15 at 15:55

score 26 · Accepted Answer · edited Feb 13 '17 at 21:58

26

Yes - you can for example use Timer class - though you must remember that it run on separate thread. Example:

private Timer timer;
public MainPage()
{        
    this.InitializeComponent();
    timer = new Timer(timerCallback, null, (int)TimeSpan.FromMinutes(1).TotalMilliseconds, Timeout.Infinite);
}

private async void timerCallback(object state)
{
    // do some work not connected with UI

    await Window.Current.CoreWindow.Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        () => {
            // do some work on UI here;
        });
}

Note that the work dispatched on UI dispatcher may not be processed right away - it depend on dispatcher's workload.

Also remember that this timer runs along with your app and won't work when app is suspended.

edited Feb 13 '17 at 21:58

Mike Keskinov

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answered Dec 14 '15 at 15:53

Romasz

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Perfect answer! – Syaiful Nizam Yahya Jan 24 '17 at 04:15
3

This threw a null reference exception, while https://stackoverflow.com/a/27698035/118153 worked for me. – Iiridayn Aug 11 '17 at 01:24
@Iiridayn It's only a way of getting dispatcher, you may also get it different ways. Just a matter of being sure that you are able to access it. – Romasz Aug 11 '17 at 07:19

score 12 · Answer 2 · answered Mar 09 '16 at 18:18

12

I resolved this issue recently using a ThreadPoolTimer class.

ThreadPoolTimer timer = ThreadPoolTimer.CreatePeriodicTimer((t) =>
        {
            //do some work \ dispatch to UI thread as needed
        }, TimeSpan.FromMinutes(1));

At present I am not aware of any advantage of this over the Timer solution already posted, but it has functioned well.

answered Mar 09 '16 at 18:18

Saxar

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Tested both solutions.ThreadPoolTimer is more accurate than Timer. Will use it. – x2. Aug 11 '16 at 10:17

score 0 · Answer 3 · edited Mar 28 '19 at 09:17

0

You may be right at your code but I have used threadpool timer instead of dispacher timer, after referring above blog.

If I talk about initial level I was using dispatcher timer for my app, what happens actually, it goes hang after every 2days of continuous standby. So I thought of threadpool timer as you are referring in this blog, but in threadpool it went hung in just 5-6 hours.

So as per my experience I think dispatcher timer is more preferable than threadpool timer.

It's just my experience of using it.

edited Mar 28 '19 at 09:17

Zoe

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answered Mar 28 '19 at 06:24

siddharth

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Can you turn this into an answer to the question at the top of this page? This is not a blog, it is a Q/A community. So you are supposed to answer questions when you start typing into the appropriatly labeled "Your Answer" field. – Yunnosch Mar 28 '19 at 06:45

Timer in UWP App which isn't linked to the UI

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