Before we dive into the technical details, let’s start with a quick history lesson, courtesy of Don Syme who worked on adding generics to .NET and then went on to design and implement F#, which is a pretty impressive set of achievements!!

Background and History

• 1999 Initial research, design and planning
  • .NET/C# Generics History: Some Photos From Feb 1999
• 1999 First ‘white paper’ published
  • More C#/.NET Generics Research Project History – The MSR white paper
  • MSR White Paper: Proposed Extensions to COM+ VOS (Draft) (pdf)
• 2001 C# Language Design Specification created
  • Some History: 2001 “GC#” (Generic C#) research project draft
  • MSR - .NET Generics Research Project - Generic C# Specification (pdf)
• 2001 Research paper published
  • Design and Implementation of Generics for the .NET CLR (pdf)
• 2004 Work completed and all bugs fixed
  • Some more .NET/C# Generics Research Project History 

using System.IO;
using WkHtmlToXSharp;
using System;

namespace Test2
{
    public class WkHtmlToXSharpTest
    {
        public static void ConvertHtmlStringToPdfTest()
        {
            using (var wk = new MultiplexingConverter())
            {
                wk.Begin += (s, e) => Console.WriteLine("Conversion begin, phase count: {0}", e.Value);
                wk.Error += (s, e) => Console.WriteLine(e.Value);
                wk.Warning += (s, e) => Console.WriteLine(e.Value);
                wk.PhaseChanged += (s, e) => Console.WriteLine("PhaseChanged: {0} - {1}", e.Value, e.Value2);
                wk.ProgressChanged += (s, e) => Console.WriteLine("ProgressChanged: {0} - {1}", e.Value, e.Value2);
                wk.Finished += (s, e) => Console.WriteLine("Finished: {0}", e.Value ? "success" : "failed!");

                wk.GlobalSettings.Margin.Top = "0cm";
                wk.GlobalSettings.Margin.Bottom = "0cm";
                wk.GlobalSettings.Margin.Left = "0cm";
                wk.GlobalSettings.Margin.Right = "0cm";

                wk.ObjectSettings.Web.EnablePlugins = false;
                wk.ObjectSettings.Web.EnableJavascript = false;
                wk.ObjectSettings.Load.Proxy = "none";

                var htmlString = File.ReadAllText(@"c:\page.xhtml");
                var tmp = wk.Convert(htmlString);

                File.WriteAllBytes(@"tst.pdf", tmp);
            }
        }
    }
}

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

private static Container defaultContainer()
        {
            var container = new Container(ioc =>
            {
                // map same interface to different concrete classes
                ioc.For<IUser>().Use<EFUserService>();
                ioc.For<IUnitOfWork>().Use(() => new ApplicationDBContext())();
            });
            container.AssertConfigurationIsValid();

            return container;
        }

  ioc.For<IUnitOfWork>().Use(() => new ApplicationDBContext())();

ErrorCS0012The type 'DbContext' is defined in an assembly that is not referenced. You must add a reference to assembly 'EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=19f9d7d4cc76b670'.BimehKosarE:\myproject\BimehKosar\BimehKosar\StrucerMap\SmObjectFactory.cs

 Ubuntu is distributed on two types of images described below.

Desktop image
The desktop image allows you to try Ubuntu without changing your computer at all, and at your option to install it permanently later. This type of image is what most people will want to use. You will need at least 384MiB of RAM to install from this image.

Server install image
The server install image allows you to install Ubuntu permanently on a computer for use as a server. It will not install a graphical user interface. 

• پیاده سازی و نامگذاری Product در Factory مربوطه متمرکز می‌شود و بدین ترتیب Client به نام و نحوه پیاده سازی Type‌های مختلف Product وابستگی نخواهد داشت.
• به راحتی می‌توان Concrete Factory مورد استفاده در برنامه را تغییر داد، بدون اینکه تاثیری در عملکرد سایر بخش‌ها داشته باشد.
• در مواردی که بیش از یک محصول برای هر خانواده وجود داشته باشد، استفاده از Abstract Factory تضمین می‌کند که Product‌های هر خانواده همه در کنار هم قرار دارند و با هم فعال و غیر فعال می‌شوند. (یا همه، یا هیچکدام) 

• Factory‌ها معمولا Singleton هستند. زیرا هر Application بطور معمول فقط به یک instance از هر Concrete Factory نیاز دارد.
  
• انتخاب Concrete Factory مناسب معمولا توسط پارامترهایی انجام می‌شود.

و کلام آخر در مورد این الگو:

• Abstract Factory یک interface یا کلاس abstract است که signature متدهای ساخت Object‌ها در آن تعریف شده است و Concrete Factory‌ها آن‌ها را implement می‌نمایند.
  
• در Abstract Factory Pattern همه Product‌های هم خانواده در Concrete Factory مربوط به آن خانواده پیاده سازی و مجتمع می‌گردند.
  
• در کدهای برنامه تنها با Abstract Factory و Abstract Product‌ها سر و کار داریم و به هیچ وجه درگیر این مساله که کدام یک از Concrete Class‌ها در برنامه مورد استفاده قرار می‌گیرند، نمی‌شویم.  
  

namespace EFCorePgExercises.Entities
{
    public class Booking
    {
       // ...

        public int MemId { set; get; }
        public virtual Member Member { set; get; }

       // ...
    }
}

var startTimes = context.Bookings
                        .Where(booking => booking.Member.FirstName == "David"
                                            && booking.Member.Surname == "Farrell")
                        .Select(booking => new { booking.StartTime })
                        .ToList();

namespace EFCorePgExercises.Entities
{
    public class Booking
    {
       // ...

        public int FacId { set; get; }
        public virtual Facility Facility { set; get; }

       // ...
    }
}

int[] tennisCourts = { 0, 1 };
var date1 = new DateTime(2012, 09, 21);
var date2 = new DateTime(2012, 09, 22);
var startTimes = context.Bookings
                        .Where(booking => tennisCourts.Contains(booking.Facility.FacId)
                                && booking.StartTime >= date1
                                && booking.StartTime < date2)
                        .Select(booking => new { booking.StartTime, booking.Facility.Name })
                        .ToList();

namespace EFCorePgExercises.Entities
{
    public class Member
    {
       // ...

        public virtual ICollection<Member> Children { get; set; }
        public virtual Member Recommender { set; get; }
        public int? RecommendedBy { set; get; }

       // ...
    }
}

var members = context.Members
                        .Where(member => member.Recommender != null)
                        .Select(member => new { member.Recommender.FirstName, member.Recommender.Surname })
                        .Distinct()
                        .OrderBy(member => member.Surname).ThenBy(member => member.FirstName)
                        .ToList();

var members = context.Members
                        .Select(member => new
                        {
                            memFName = member.FirstName,
                            memSName = member.Surname,
                            recFName = member.Recommender.FirstName ?? "",
                            recSName = member.Recommender.Surname ?? ""
                        })
                        .OrderBy(member => member.memSName).ThenBy(member => member.memFName)
                        .ToList();

A LEFT JOIN B            A LEFT OUTER JOIN B
A RIGHT JOIN B           A RIGHT OUTER JOIN B
A FULL JOIN B            A FULL OUTER JOIN B
A INNER JOIN B           A JOIN B

namespace EFCorePgExercises.Entities
{
    public class Booking
    {
       // ...

        public int FacId { set; get; }
        public virtual Facility Facility { set; get; }

        public int MemId { set; get; }
        public virtual Member Member { set; get; }

       // ...
    }
}

namespace EFCorePgExercises.Entities
{
    public class Member
    {
       // ...

        public virtual ICollection<Booking> Bookings { set; get; }
    }
}

int[] tennisCourts = { 0, 1 };
var members = context.Members
                        .SelectMany(x => x.Bookings)
                        .Where(booking => tennisCourts.Contains(booking.Facility.FacId))
                        .Select(booking => new
                        {
                            Member = booking.Member.FirstName + " " + booking.Member.Surname,
                            Facility = booking.Facility.Name
                        })
                        .Distinct()
                        .OrderBy(x => x.Member)
                        .ToList();

var date1 = new DateTime(2012, 09, 14);
var date2 = new DateTime(2012, 09, 15);

var items = context.Members
                        .SelectMany(x => x.Bookings)
                        .Where(booking => booking.StartTime >= date1 && booking.StartTime < date2
                        && (
                            (((booking.Slots * booking.Facility.GuestCost) > 30) && (booking.MemId == 0)) ||
                            (((booking.Slots * booking.Facility.MemberCost) > 30) && (booking.MemId != 0))
                        ))
                        .Select(booking => new
                        {
                            Member = booking.Member.FirstName + " " + booking.Member.Surname,
                            Facility = booking.Facility.Name,
                            Cost = booking.MemId == 0 ?
                                        booking.Slots * booking.Facility.GuestCost
                                        : booking.Slots * booking.Facility.MemberCost
                        })
                        .Distinct()
                        .OrderByDescending(x => x.Cost)
                        .ToList();

var members = context.Members
                        .Select(member =>
                        new
                        {
                            Member = member.FirstName + " " + member.Surname,
                            Recommender = context.Members
                                .Where(recommender => recommender.MemId == member.RecommendedBy)
                                .Select(recommender => recommender.FirstName + " " + recommender.Surname)
                                .FirstOrDefault() ?? ""
                        })
                        .Distinct()
                        .OrderBy(member => member.Member)
                        .ToList();

var date1 = new DateTime(2012, 09, 14);
var date2 = new DateTime(2012, 09, 15);

var items = context.Members
                        .SelectMany(x => x.Bookings)
                        .Where(booking => booking.StartTime >= date1 && booking.StartTime < date2)
                        .Select(booking => new
                        {
                            Member = booking.Member.FirstName + " " + booking.Member.Surname,
                            Facility = booking.Facility.Name,
                            Cost = booking.MemId == 0 ?
                                        booking.Slots * booking.Facility.GuestCost
                                        : booking.Slots * booking.Facility.MemberCost
                        })
                        .Where(x => x.Cost > 30)
                        .Distinct()
                        .OrderByDescending(x => x.Cost)
                        .ToList();