Windows Service

[EzehM]

I am writing a piece of code that monitors files in a directory and copies them onto another directory, by calling other methods etc. I have a setting in the registry that determines the polling intervals. This part of the code is in an endless loop. I have written this as a clean .exe, but now I want to make it a Windows service. I have just started reading on Windows services, and I noticed that the OnStart() function where I had planned to place my code requires that it returns almost immediately (30 seconds). My question therefore is this: How can I then write this bit of code as a service. What do I need to place in the OnStart() function, and still make my application work? Especially since I cant loop indefinitely in the OnStart() function.

Many thanks in advance

 

[B00gyeMan]

Here is what you're trying to do (it uses the FileSystemWatcher which elliminates the need of an endless loop):

http://www.codeproject.com/csharp/FileWatcherWinServiceCSha.asp

P.S.: Google is your friend

 

[EzehM]

Thanks for the tip, I have explored the FileSystemWatcher object, but because of the involvedness in our design and the use of various configuration elements to determine what directories to monitor, remove, add etc. The idea of using it was discarded. I have something that works, but all I need to know is what to add to the OnStart() method. I have just read a little bit about using the Timer object, and in some cases spawning a separate thread to call the function that polls while returning quickly to OnStart().

 

[jmeckley]

i created a service that runs once a day. turns on, run code, turn off. if I do this

Start()
{
   new MyTask().Preform();
   this.Stop();
}

then the service will work, but an error is logged in the event log stating the service may not have started, or an error occurred. instead I need to do this

Start()
{
   this.timer.Start();
}

Timer_Elapsed()
{
   this.timer.Stop();
   new MyTask().Preform();
   this.Stop();
}

now the order of events is
1. start service
2. service starts timer
3. service completes starting
4. timer event executes my task
5. service is stopped
everything runs as before, and no errors logged to the event log. full code sample:

public class MyService : BaseService
{
   private Timer timer;

   public MyService()
   {
      this.timer = new Timer();
      this.timer.Stop();
      this.timer.Elapsed += new TimerHandler(timer_Elapsed);
      this.timer.Ticks = 2000; //2 seconds
   }

   protected override void OnStart()
   {
      this.timer.Start();
   }

   protected override void OnStop()
   {
      this.timer.Stop();
   }

   private void timer_Elapsed(object sender, TimerEventArgs e)
   {
      this.timer.Stop();
      new MyTask().Preform();
      this.Stop();
   }
}

if you don't want to automatically stop the service change the timer event to this

   private void timer_Elapsed(object sender, TimerEventArgs e)
   {
      this.timer.Stop();
      new MyTask().Preform();
      this.timer.Start();
   }

Jason Meckley
Programmer
Specialty Bakers, Inc.

 

[EzehM]

Thanks Jason, just what I needed.

 

[JohnYingling]

Another way is start a Thread in the Start Event.

http://www.moldyoldy.com/VBComparedemo

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