How is code executed in a window service?

Question

I was asked to develop a C# windows service. However I am used to create GUI with User Input.

Since windows services are automated, I would like to know how is the code executed.

I mean how can I control the flow?

Could someone clarify? I don't find a lot of information about window services...

Answer 1

Windows service starts exection from OnStart, usually a repeated execution starts from here could be a timer for instance. When service stops OnStop method is called. This article could be a good starting point.

protected override void OnStart(string[] args)
  {
    base.OnStart(args);

    //TODO: place your start code here
  }

  protected override void OnStop()
  {
    base.OnStop();

    //TODO: clean up any variables and stop any threads
  }

Answer 2

The code is started in the OnStart()

protected override void OnStart(string[] args)
{
    // Equivalent of Main()
    // Run threads here before timeout so OS knows it has started
}

Which you usually start a thread from to another function so that OnStart() can return and the service can start.

Same with OnStop and OnShutdown etc, where you would clean everything up.

Answer 3

protected override void OnStart(string[] args)
    {
        try
        {
            timer.AutoReset = true;
            timer.Enabled = true;
            timer.Start();

            serviceThread = new Thread(new ThreadStart(Delete));
            clientCleanupThread = new Thread(new ThreadStart(removeExpirery));
            enableAutoSubscribeProduct = new Thread(new ThreadStart(Products));

            serviceThread.Start();
            clientCleanupThread.Start();


            enableAutoSubscribeProduct.Start();


        }
        catch (Exception ex)
        {

            Log.Error("Error on thread start " + ex.Message);
        }
    }