.NET console application as Windows service

Question

I usually use the following techinque to run the same app as a console application or as a service:

using System.ServiceProcess

public static class Program
{
    #region Nested classes to support running as service
    public const string ServiceName = "MyService";

    public class Service : ServiceBase
    {
        public Service()
        {
            ServiceName = Program.ServiceName;
        }

        protected override void OnStart(string[] args)
        {
            Program.Start(args);
        }

        protected override void OnStop()
        {
            Program.Stop();
        }
    }
    #endregion
    
    static void Main(string[] args)
    {
        if (!Environment.UserInteractive)
            // running as service
            using (var service = new Service())
                ServiceBase.Run(service);
        else
        {
            // running as console app
            Start(args);

            Console.WriteLine("Press any key to stop...");
            Console.ReadKey(true);

            Stop();
        }
    }
    
    private static void Start(string[] args)
    {
        // onstart code here
    }

    private static void Stop()
    {
        // onstop code here
    }
}

Environment.UserInteractive is normally true for console app and false for a service. Techically, it is possible to run a service in user-interactive mode, so you could check a command-line switch instead.

I've had great success with TopShelf.

TopShelf is a Nuget package designed to make it easy to create .NET Windows apps that can run as console apps or as Windows Services. You can quickly hook up events such as your service Start and Stop events, configure using code e.g. to set the account it runs as, configure dependencies on other services, and configure how it recovers from errors.

From the Package Manager Console (Nuget):

Install-Package Topshelf

Refer to the code samples to get started.

Example:

HostFactory.Run(x =>                                 
{
    x.Service<TownCrier>(s =>                        
    {
       s.ConstructUsing(name=> new TownCrier());     
       s.WhenStarted(tc => tc.Start());              
       s.WhenStopped(tc => tc.Stop());               
    });
    x.RunAsLocalSystem();                            

    x.SetDescription("Sample Topshelf Host");        
    x.SetDisplayName("Stuff");                       
    x.SetServiceName("stuff");                       
}); 

TopShelf also takes care of service installation, which can save a lot of time and removes boilerplate code from your solution. To install your .exe as a service you just execute the following from the command prompt:

myservice.exe install -servicename "MyService" -displayname "My Service" -description "This is my service."

You don't need to hook up a ServiceInstaller and all that - TopShelf does it all for you.

So here's the complete walkthrough:

1. Create new Console Application project (e.g. MyService)
2. Add two library references: System.ServiceProcess and System.Configuration.Install
3. Add the three files printed below
4. Build the project and run "InstallUtil.exe c:\path\to\MyService.exe"
5. Now you should see MyService on the service list (run services.msc)

*InstallUtil.exe can be usually found here: C:\windows\Microsoft.NET\Framework\v4.0.30319\InstallUtil.ex‌​e

Program.cs

using System;
using System.IO;
using System.ServiceProcess;

namespace MyService
{
    class Program
    {
        public const string ServiceName = "MyService";

        static void Main(string[] args)
        {
            if (Environment.UserInteractive)
            {
                // running as console app
                Start(args);

                Console.WriteLine("Press any key to stop...");
                Console.ReadKey(true);

                Stop();
            }
            else
            {
                // running as service
                using (var service = new Service())
                {
                    ServiceBase.Run(service);
                }
            }
        }

        public static void Start(string[] args)
        {
            File.AppendAllText(@"c:\temp\MyService.txt", String.Format("{0} started{1}", DateTime.Now, Environment.NewLine));
        }

        public static void Stop()
        {
            File.AppendAllText(@"c:\temp\MyService.txt", String.Format("{0} stopped{1}", DateTime.Now, Environment.NewLine));
        }
    }
}

MyService.cs

using System.ServiceProcess;

namespace MyService
{
    class Service : ServiceBase
    {
        public Service()
        {
            ServiceName = Program.ServiceName;
        }

        protected override void OnStart(string[] args)
        {
            Program.Start(args);
        }

        protected override void OnStop()
        {
            Program.Stop();
        }
    }
}

MyServiceInstaller.cs

using System.ComponentModel;
using System.Configuration.Install;
using System.ServiceProcess;

namespace MyService
{
    [RunInstaller(true)]
    public class MyServiceInstaller : Installer
    {
        public MyServiceInstaller()
        {
            var spi = new ServiceProcessInstaller();
            var si = new ServiceInstaller();

            spi.Account = ServiceAccount.LocalSystem;
            spi.Username = null;
            spi.Password = null;

            si.DisplayName = Program.ServiceName;
            si.ServiceName = Program.ServiceName;
            si.StartType = ServiceStartMode.Automatic;

            Installers.Add(spi);
            Installers.Add(si);
        }
    }
}

Here is a newer way of how to turn a Console Application to a Windows Service as a Worker Service based on the latest .Net Core 3.1.

If you create a Worker Service from Visual Studio 2019 it will give you almost everything you need for creating a Windows Service out of the box, which is also what you need to change to the console application in order to convert it to a Windows Service.

Here are the changes you need to do:

Install the following NuGet packages

Install-Package Microsoft.Extensions.Hosting.WindowsServices -Version 3.1.0
Install-Package Microsoft.Extensions.Configuration.Abstractions -Version 3.1.0

Change Program.cs to have an implementation like below:

using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

namespace ConsoleApp
{
    class Program
    {
        public static void Main(string[] args)
        {
            CreateHostBuilder(args).UseWindowsService().Build().Run();
        }

        private static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureServices((hostContext, services) =>
                {
                    services.AddHostedService<Worker>();
                });
    }
}

and add Worker.cs where you will put the code which will be run by the service operations:

using Microsoft.Extensions.Hosting;
using System.Threading;
using System.Threading.Tasks;

namespace ConsoleApp
{
    public class Worker : BackgroundService
    {
        protected override async Task ExecuteAsync(CancellationToken stoppingToken)
        {
            //do some operation
        }

        public override Task StartAsync(CancellationToken cancellationToken)
        {
            return base.StartAsync(cancellationToken);
        }

        public override Task StopAsync(CancellationToken cancellationToken)
        {
            return base.StopAsync(cancellationToken);
        }
    }
}

When everything is ready, and the application has built successfully, you can use sc.exe to install your console application exe as a Windows Service with the following command:

sc.exe create DemoService binpath= "path/to/your/file.exe"

Firstly I embed the console application solution into the windows service solution and reference it.

Then I make the console application Program class public

/// <summary>
/// Hybrid service/console application
/// </summary>
public class Program
{
}

I then create two functions within the console application

    /// <summary>
    /// Used to start as a service
    /// </summary>
    public void Start()
    {
        Main();
    }

    /// <summary>
    /// Used to stop the service
    /// </summary>
    public void Stop()
    {
       if (Application.MessageLoop)
            Application.Exit();   //windows app
        else
            Environment.Exit(1);  //console app
    }

Then within the windows service itself I instantiate the Program and call the Start and Stop functions added within the OnStart and OnStop. See below

class WinService : ServiceBase
{
    readonly Program _application = new Program();

    /// <summary>
    /// The main entry point for the application.
    /// </summary>
    static void Main()
    {
        ServiceBase[] servicesToRun = { new WinService() };
        Run(servicesToRun);
    }

    /// <summary>
    /// Set things in motion so your service can do its work.
    /// </summary>
    protected override void OnStart(string[] args)
    {
        Thread thread = new Thread(() => _application.Start());
        thread.Start();
    }

    /// <summary>
    /// Stop this service.
    /// </summary>
    protected override void OnStop()
    {
        Thread thread = new Thread(() => _application.Stop());
        thread.Start();
    }
}

This approach can also be used for a windows application / windows service hybrid