Fire timer_elapsed immediately from OnStart in windows service

Question

I'm using a System.Timers.Timer and I've got code like the following in my OnStart method in a c# windows service.

timer = new Timer();
timer.Elapsed += timer_Elapsed;
timer.Enabled = true;
timer.Interval = 3600000;
timer.Start();

This causes the code in timer_Elapsed to be executed every hour starting from an hour after I start the service. Is there any way to get it to execute at the point at which I start the service and then every hour subsequently?

The method called by timer_Elapsed takes too long to run to call it directly from OnStart.

Any issues if you call it after timer.Start() ? – V4Vendetta Apr 21 '11 at 10:33 — V4Vendetta, Apr 21 '11 at 10:33

Hans Passant · Accepted Answer · 2014-09-17T11:29:28.930

20

Just start a threadpool thread to call the worker function, just like Timer does. Like this:

        timer.Elapsed += timer_Elapsed;
        ThreadPool.QueueUserWorkItem((_) => DoWork());
    ...

    void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e) {
        DoWork();
    }

    void DoWork() {
        // etc...
    }

edited Sep 17 '14 at 11:29

answered Apr 21 '11 at 10:36

Hans Passant

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score 2 · Answer 2 · answered Jun 02 '15 at 14:28

If you want your Timer to be fired immediately then you could simply just initialize the Timer object without a specified interval (it will default to 100ms which is almost immediately :P), then set the interval within the called function to whatever you like. Here is an example of what I use in my Windows Service:

private static Timer _timer;

protected override void OnStart(string[] args)
{
    _timer = new Timer(); //This will set the default interval
    _timer.AutoReset = false;
    _timer.Elapsed = OnTimer;
    _timer.Start();
}

private void OnTimer(object sender, ElapsedEventArgs args)
{
    //Do some work here
    _timer.Stop();
    _timer.Interval = 3600000; //Set your new interval here
    _timer.Start();
}

score 2 · Answer 3 · answered Aug 10 '11 at 05:41

Use AutoReset Property of System.Timers.Timer and set it value to "true". No need to use timer.Start() because it does the same job as timer.Enabled = true;

timer = new Timer();
timer.Elapsed += timer_Elapsed;
timer.Enabled = true;
timer.Interval = 3600000;
timer.AutoReset = true;

AutoReset = true will set a value indicating that the Timer should raise the Elapsed event each time when the specified interval elapses.

score 1 · Answer 4 · answered Apr 21 '11 at 10:55

1

Use System.Threading.Timer class instead of System.Timers.Timer as this type is just a wrapper for Threading Timer.

It also suits your requirement.

 System.Threading.Timer timer =
                new System.Threading.Timer(this.DoWork, this, 0, 36000);

Here are the details.

answered Apr 21 '11 at 10:55

Vijay Sirigiri

4,583
28
31

I did that but here at least did not worked. It runs the method just before the time is started but it runs inside the onStart(). – Thiago Jun 28 '12 at 19:25

Fire timer_elapsed immediately from OnStart in windows service

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