// https://www.dotnetcurry.com/dotnet/1092/dotnet-design-patterns

using System;

using System.Linq.Expressions;

​

public class MailManager

{

    public MailManager To(string address)

    {

        Console.WriteLine("To: " + address);

        return this;

    }

​

    public MailManager From(string address)

    {

        Console.WriteLine("From: " + address);

        return this;

    }

​

    public MailManager Subject(string subject)

    {

        Console.WriteLine("Subject: " + subject);

        return this;

    }

​

    public MailManager Body(string body)

    {

        Console.WriteLine("Body: " + body);

        return this;

    }

​

    public static void Send(Action<MailManager> action)

    {

        action(new MailManager());

        Console.WriteLine("Sent!");

    }

}

​

public class Program

{

    public static void Main(string[] args)

    {

        MailManager.Send(mail => mail.From("alan@developer.com").To("jonsmith@developer.com").Subject("Code sample").Body("This is an the email body!"));

    }

}