using System;

using System.ComponentModel;

using System.Runtime.CompilerServices;

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

}

​

public class ViewModel: INotifyPropertyChanged

{

    private Service service;

​

    private bool enabled = false;

    public bool Enabled

    {

        get => this.enabled;

        set  

        {

            if(value) 

                this.service.Start(); 

            else 

                this.service.Stop();

        }

    }

    public ViewModel()

    {

        this.service = new Service();

        this.service.StatusChanged += (o, e) => { enabled = e; Notify(nameof(Enabled)); };

    }

    public event PropertyChangedEventHandler PropertyChanged;

    protected void Notify([CallerMemberName] string property = null)

    {

        this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(property));

    }

}

​

public class Service

{

    internal event EventHandler<bool> StatusChanged;

    internal bool IsRunning = false;

    internal void Start()

    {

        // start whatever

        this.IsRunning = true;

        this.StatusChanged?.Invoke(this, this.IsRunning);

    }

    internal void Stop()

    {

        // stop whatever

        this.IsRunning = false;

        this.StatusChanged?.Invoke(this, this.IsRunning);

    }

}