Timer in Windows Service not firing ElapsedEventHandler

I have a windows service written in C# that executes a method correctly. I added a timer to schedule the method execution and it doesn't seem to fire the ElapsedEventHandler event.

System.Timers.Timer timer = new System.Timers.Timer();

public LabelService()
        {
            InitializeComponent();
            timer.Elapsed += new ElapsedEventHandler(timer_Elapsed);
        }


public void SetTimer()
        {
            DateTime nextRunTime = GetNextRunTime();
            var ts = nextRunTime - DateTime.Now;
            timer.Interval = ts.TotalMilliseconds;
            timer.AutoReset = false;
            timer.Start();
        }

void timer_Elapsed(object source, ElapsedEventArgs e)
        {
           // ** never gets here **
            timer.Stop();
              // run some code
            SetTimer();
        }

I can run and hit a breakpoint at timer.Start(); so I k开发者_运维问答now that's being done, but it never falls into the timer_Elapsed method. (For testing I change ts.TotalMilliseconds to 1000) Any ideas?

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"If Enabled is set to true and AutoReset is set to false, the Timer raises the Elapsed event only once, the first time the interval elapses. When Enabled is true and AutoReset is true, the Timer continues to raise the Elapsed event on the specified interval."

So I think you gotta set

timer.AutoReset = true;

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I know this is old, but for anyone else with the same problem I was able to work around this by using;

public void StartTimer()
{
    _timer.Interval = _pollingIntervalMilliseconds;
    _timer.Enabled = true;
    _timer.AutoReset = false; // We must manually restart the timer when we have finished processing
    _timer.Elapsed += CheckForUpdates;
    _timer.Start();
    if (Environment.UserInteractive)
    {
        Console.WriteLine("System now running, press a key to Stop");
        Console.ReadKey();
    }
}
private void CheckForUpdates(object sender, ElapsedEventArgs e)
{
    Console.WriteLine("Checking For Update");
    DoSomethingSlow();
    _timer.Start(); // restarts the timer to hit this method again after the next interval
}

It will keep hitting the Elapsed Event until you hit a key to exit

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From comments on the question you say you are calling it like this:

#if (!DEBUG) 
    ServiceBase[] ServicesToRun; 
    ServicesToRun = new ServiceBase[] { new LabelLoader() }; 
    ServiceBase.Run(ServicesToRun); 
#else 
    LabelLoader ll = new LabelLoader(); 
    ll.Start(); 
#endif

If you are in debug mode that means your main method is this:

    LabelLoader ll = new LabelLoader(); 
    ll.Start(); 

This means that once it has run these two lines the program finishes running and presumably exits. It doesn't matter what your timer is up to, the program has quit and thus your timer never fires.

I'd advise testing your ll with a better harness. Personally I use a winform type interface and just have a start button to mimic the service start (which will then have your code in the button click). Once I think I have that code running as I want I then test it in a service environment.