Millisecond interval for DispatcherTimer

Question

I'm using a DispatcherTimer to call a void in C#:

        counter = new System.Windows.Threading.DispatcherTimer();
        counter.Tick += new EventHandler(counter_Tick);
        counter.Interval = new TimeSpan(0, 0, 1);
        counter.Start();

However I would like the interval to be a few milliseconds, TimeSpan's parameters are hours,minutes,seconds and only accepts integers (as far as I can see). Is there a work around for DispatcherTimer? I've tried Timer but I cannot use it (missing reference apparently)

Thanks in advance.

`TimeSpan` has a constructor that takes milliseconds: [see MSDN](https://msdn.microsoft.com/en-us/library/6c7z43tw(v=vs.110).aspx). Basically, use `new TimeSpan(0, 0, 0, 0, milliseconds);` — Der Kommissar, Jun 01 '15 at 19:35

score 9 · Answer 1 · answered Jun 02 '15 at 05:25

9

Another way

  counter.Interval = TimeSpan.FromMilliseconds(1);

answered Jun 02 '15 at 05:25

Null Pointer

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score 7 · Accepted Answer · answered Jun 01 '15 at 19:40

The TimeSpan object has a constructor that takes milliseconds as a parameter:

MSDN has the details: https://msdn.microsoft.com/en-us/library/6c7z43tw(v=vs.110).aspx

Basically, replace new TimeSpan(0, 0, 1) with new TimeSpan(0, 0, 0, 0, millisecondTimeout).

score 2 · Answer 3 · answered Sep 09 '16 at 15:00

Although @EBrown's answer already tells you how to use milliseconds with a DispatcherTimer, its precision is supposedly around 15-20 ms, and the errors add up at each iteration, which makes it a bit impractical.

However it is possible to work around this issue by starting a System.Diagnostics.StopWatch at the same time as the DispatcherTimer and checking the StopWatch.ElapsedMilliseconds inside the Tick Event with a smaller time step, and that seems to give more precise results. It also works with a System.Timers.Timer.

Here's a short example based on a WPF program I made.

private void StartTimers(object sender, RoutedEventArgs e)
{
    dtimer = new DispatcherTimer();
    dtimer.Tick += new EventHandler(dTimer_Tick);
    dtimer.Interval = TimeSpan.FromMilliseconds(1);  // the small time step

    stopWatch = new StopWatch();

    dTimer.Start();
    stopWatch.Start();
}

private void dTimer_Tick(object sender, EventArgs e)
{        
     currentTime = stopWatch.ElapsedMilliseconds;
        if (currentTime - oldTime > interval)
        {
            oldTime = currentTime;
            DoStuff();
        }
}

Using StopWatch.Restart in the Tick Event to do iterations will have the same error problem the DispatchTimer causes, because it's going to restart when the DispatchTimer event is fired.

Millisecond interval for DispatcherTimer

3 Answers3