1.  URI-based versioning 
   
2.  Header-based versioning 
   
3.  Media type-based versioning 
   

 public class ItemsController : ApiController   
 {
        [ResponseType(typeof(ItemViewModel))]
        public IHttpActionResult Get(int id)
        {
            var viewModel = new ItemViewModel { Id = id, Name = "PS4", Country = "Japan" };
            return Ok(viewModel);
        }
    }
 public class ItemsV2Controller : ApiController
    {
        [ResponseType(typeof(ItemV2ViewModel))]
        public IHttpActionResult Get(int id)
        {
            var viewModel = new ItemV2ViewModel { Id = id, Name = "Xbox One", Country = "USA", Price = 529.99 };
            return Ok(viewModel);
        }
    }

config.Routes.MapHttpRoute("ItemsV2", "api/v2/items/{id}", new
{
    controller = "ItemsV2",
    id = RouteParameter.Optional
});
config.Routes.MapHttpRoute("Items", "api/items/{id}", new
{
    controller = "Items",
    id = RouteParameter.Optional
});
config.Routes.MapHttpRoute(
    name: "DefaultApi",
    routeTemplate: "api/{controller}/{id}",
    defaults: new { id = RouteParameter.Optional }
);

public class VersionFinder
    {
        private static bool NeedsUriVersioning(HttpRequestMessage request, out string version)
        {
            var routeData = request.GetRouteData();
            if (routeData != null)
            {
                object versionFromRoute;
                if (routeData.Values.TryGetValue(nameof(version), out versionFromRoute))
                {
                    version = versionFromRoute as string;
                    if (!string.IsNullOrWhiteSpace(version))
                    {
                        return true;
                    }
                }
            }
            version = null;
            return false;
        }
        private static int VersionToInt(string versionString)
        {
            int version;
            if (string.IsNullOrEmpty(versionString) || !int.TryParse(versionString, out version))
                return 0;
            return version;
        }
        public static int GetVersionFromRequest(HttpRequestMessage request)
        {
            string version;

            return NeedsUriVersioning(request, out version) ? VersionToInt(version) : 0;
        }
    }

 public class VersionAwareControllerSelector : DefaultHttpControllerSelector
    {
        public VersionAwareControllerSelector(HttpConfiguration configuration) : base(configuration) { }
        public override string GetControllerName(HttpRequestMessage request)
        {
            var controllerName = base.GetControllerName(request);
            var version = VersionFinder.GetVersionFromRequest(request);
                
        return version > 0 ? GetVersionedControllerName(request, controllerName, version) : controllerName;
        }
        private string GetVersionedControllerName(HttpRequestMessage request, string baseControllerName,
        int version)
        {
            var versionControllerName = $"{baseControllerName}v{version}";
            HttpControllerDescriptor descriptor;
            if (GetControllerMapping().TryGetValue(versionControllerName, out descriptor))
            {
                return versionControllerName;
            }

            throw new HttpResponseException(request.CreateErrorResponse(
            HttpStatusCode.NotFound,
                $"No HTTP resource was found that matches the URI {request.RequestUri} and version number {version}"));
        }
    }

config.Services.Replace(typeof(IHttpControllerSelector), new VersionAwareControllerSelector(config));

[RoutePrefix("api/v1/Items")]
    public class ItemsController : ApiController
    {
        [ResponseType(typeof(ItemViewModel))]
        [Route("{id:int}")]
        public IHttpActionResult Get(int id)
        {
            var viewModel = new ItemViewModel { Id = id, Name = "PS4", Country =        "Japan" };
            return Ok(viewModel);
        }
    }


 [RoutePrefix("api/V2/Items")]
    public class ItemsV2Controller : ApiController
    {
        [ResponseType(typeof(ItemV2ViewModel))]
        [Route("{id:int}")]
        public IHttpActionResult Get(int id)
        {
            var viewModel = new ItemV2ViewModel { Id = id, Name = "Xbox One", Country = "USA", Price = 529.99 };
            return Ok(viewModel);
        }
    }

var constraintsResolver = new DefaultInlineConstraintResolver();
            constraintsResolver.ConstraintMap.Add(nameof(VersionConstraint), typeof
            (VersionConstraint));
config.MapHttpAttributeRoutes(constraintsResolver);

  public class NamespaceControllerSelector : IHttpControllerSelector
    {
        private readonly HttpConfiguration _configuration;
        private readonly Lazy<Dictionary<string, HttpControllerDescriptor>> _controllers;
        public NamespaceControllerSelector(HttpConfiguration config)
        {
            _configuration = config;
            _controllers = new Lazy<Dictionary<string,
                HttpControllerDescriptor>>(InitializeControllerDictionary);
        }
        public HttpControllerDescriptor SelectController(HttpRequestMessage request)
        {
            var routeData = request.GetRouteData();
            if (routeData == null)
            {
                throw new HttpResponseException(HttpStatusCode.NotFound);
            }

            var controllerName = GetControllerName(routeData);
            if (controllerName == null)
            {
                throw new HttpResponseException(HttpStatusCode.NotFound);
            }
            var version = GetVersion(routeData);
            if (version == null)
            {
                throw new HttpResponseException(HttpStatusCode.NotFound);
            }
            var controllerKey = string.Format(CultureInfo.InvariantCulture, "{0}.{1}",
                version, controllerName);
            HttpControllerDescriptor controllerDescriptor;
            if (_controllers.Value.TryGetValue(controllerKey, out controllerDescriptor))
            {
                return controllerDescriptor;
            }
            throw new HttpResponseException(HttpStatusCode.NotFound);
        }
        public IDictionary<string, HttpControllerDescriptor> GetControllerMapping()
        {
            return _controllers.Value;
        }
        private Dictionary<string, HttpControllerDescriptor> InitializeControllerDictionary()
        {
            var dictionary = new Dictionary<string,
                HttpControllerDescriptor>(StringComparer.OrdinalIgnoreCase);
            var assembliesResolver = _configuration.Services.GetAssembliesResolver();
            var controllersResolver = _configuration.Services.GetHttpControllerTypeResolver();
            var controllerTypes = controllersResolver.GetControllerTypes(assembliesResolver);
            foreach (var controllerType in controllerTypes)
            {
                var segments = controllerType.Namespace.Split(Type.Delimiter);
                var controllerName =
                    controllerType.Name.Remove(controllerType.Name.Length -
                                               DefaultHttpControllerSelector.ControllerSuffix.Length);
                var controllerKey = string.Format(CultureInfo.InvariantCulture, "{0}.{1}",
                    segments[segments.Length - 1], controllerName);

                if (!dictionary.Keys.Contains(controllerKey))
                {
                    dictionary[controllerKey] = new HttpControllerDescriptor(_configuration,
                        controllerType.Name,
                        controllerType);
                }
            }
            return dictionary;
        }
        private static T GetRouteVariable<T>(IHttpRouteData routeData, string name)
        {
            object result;
            if (routeData.Values.TryGetValue(name, out result))
            {
                return (T)result;
            }
            return default(T);
        }
        private static string GetControllerName(IHttpRouteData routeData)
        {
            var subroute = routeData.GetSubRoutes().FirstOrDefault();
            var dataTokenValue = subroute?.Route.DataTokens.First().Value;
            var controllerName =
                ((HttpActionDescriptor[])dataTokenValue)?.First().ControllerDescriptor.ControllerName.Replace("Controller", string.Empty);
            return controllerName;
        }
        private static string GetVersion(IHttpRouteData routeData)
        {
            var subRouteData = routeData.GetSubRoutes().FirstOrDefault();
            return subRouteData == null ? null : GetRouteVariable<string>(subRouteData, "version");
        }
    }

public IDictionary<string, HttpControllerDescriptor> GetControllerMapping()

 public static class WebApiConfig
    {
        public static void Register(HttpConfiguration config)
        {
            var constraintsResolver = new DefaultInlineConstraintResolver();
            constraintsResolver.ConstraintMap.Add(nameof(VersionConstraint), typeof
            (VersionConstraint));

            config.MapHttpAttributeRoutes(constraintsResolver);

            config.Services.Replace(typeof(IHttpControllerSelector), new NamespaceControllerSelector(config));

        }
    }

public class HeaderVersionConstraint : IHttpRouteConstraint
    {
        private const string VersionHeaderName = "api-version";

        public HeaderVersionConstraint(int allowedVersion)
        {
            AllowedVersion = allowedVersion;
        }

        public int AllowedVersion { get; }

        public bool Match(HttpRequestMessage request, IHttpRoute route, string parameterName,
            IDictionary<string, object> values,
            HttpRouteDirection routeDirection)
        {
            if (!request.Headers.Contains(VersionHeaderName)) return false;

            var version = request.Headers.GetValues(VersionHeaderName).FirstOrDefault();

            return VersionToInt(version) == AllowedVersion;
        }
        private static int VersionToInt(string versionString)
        {
            int version;
            if (string.IsNullOrEmpty(versionString) || !int.TryParse(versionString, out version))
                return 0;
            return version;
        }
    }

public sealed class HeaderVersionedRouteAttribute : RouteFactoryAttribute
    {
        public HeaderVersionedRouteAttribute(string template) : base(template)
        {
            Order = -1;
        }

        public int Version { get; set; }

        public override IDictionary<string, object> Constraints => new HttpRouteValueDictionary
        {
            {"", new HeaderVersionConstraint(Version)}
        };
    }

    [RoutePrefix("api/items")]
    public class ItemsController : ApiController
    {
        [ResponseType(typeof(ItemViewModel))]
        [HeaderVersionedRoute("{id}", Version = 1)]
        public IHttpActionResult Get(int id)
        {
            var viewModel = new ItemViewModel { Id = id, Name = "PS4", Country = "Japan" };
            return Ok(viewModel);
        }
    }
  [RoutePrefix("api/items")]
    public class ItemsV2Controller : ApiController
    {
        [ResponseType(typeof(ItemV2ViewModel))]
        [HeaderVersionedRoute("{id}", Version = 2)]
        public IHttpActionResult Get(int id)
        {
            var viewModel = new ItemV2ViewModel { Id = id, Name = "Xbox One", Country = "USA", Price = 529.99 };
            return Ok(viewModel);
        }
    }

namespace DomainEventsSample.Framework.Eventing.DomainEvents
{
    public interface IDomainEvent : ITransientDependency
    {
    }
}

1. متد Raise مربوط به Engine برای رویداد خاصی فراخوانی می‌شود.
2. با استفاده از یک IOC Container، تمام هندلرهای مربوط به رویداد جمع آوری می‌شود.
3. متد Handle مربوط به تک تک هندلرها، فراخوانی خواهد شد.

namespace DomainEventsSample.Framework.Eventing.DomainEvents
{
    public interface IDomainEventEngine : ISingletonDependency
    {
        void Raise<T>(T domainEvent) where T : IDomainEvent;
    }
}

namespace DomainEventsSample.Framework.Eventing.DomainEvents
{
    public class DomainEventEngine : IDomainEventEngine
    {
        private readonly IContainer _container;

        public DomainEventEngine(IContainer container)
        {
            _container = container;
        }

        public void Raise<T>(T domainEvent) where T : IDomainEvent
        {
            foreach (var handler in _container.GetAllInstances<IDomainEventHandler<T>>())
                try
                {
                    handler.Handle(domainEvent);
                }
                catch (Exception)
                {
                    if (domainEvent.IsAdvisable && handler.IsAdvisable)
                        throw;
                }
        }
    }
}

namespace DomainEventsSample.Framework.Domain.Events
{
    public abstract class EntityDomainEvent<TEntity> : IDomainEvent
        where TEntity : Entity
    {
        protected EntityDomainEvent(TEntity entity)
        {
            Entity = entity;
        }

        public TEntity Entity { get; }
    }
}

کلاس بالا به عنوان کلاس پایه یکسری رویداد مشترک مابین Entity‌های سیستم در نظر گرفته شده است.

namespace DomainEventsSample.Framework.Domain.Events
{
    public class EntityCreatingEvent<TEntity> : EntityDomainEvent<TEntity>
        where TEntity : Entity
    {
        public EntityCreatingEvent(TEntity entity) : base(entity)
        {
        }
    }
}
namespace DomainEventsSample.Framework.Domain.Events
{
    public class EntityCreatedEvent<TEntity> : EntityDomainEvent<TEntity>
        where TEntity : Entity
    {
        public EntityCreatedEvent(TEntity entity) : base(entity)
        {
        }
    }
}

این رویدادها مربوط به زمان قبل و بعد از ایجاد یک Entity می‌باشند.

namespace DomainEventsSample.Framework.Domain.Events
{
    public class EntityEditingEvent<TEntity> : EntityDomainEvent<TEntity>
        where TEntity : Entity
    {
        public EntityEditingEvent(TEntity entity) : base(entity)
        {
        }
    }
}
namespace DomainEventsSample.Framework.Domain.Events
{
    public class EntityEditedEvent<TEntity> : EntityDomainEvent<TEntity>
        where TEntity : Entity
    {
        public EntityEditedEvent(TEntity entity) : base(entity)
        {
        }
    }
}

namespace DomainEventsSample.Framework.Domain.Events
{
    public class EntityDeletingEvent<TEntity> : EntityDomainEvent<TEntity>
        where TEntity : Entity
    {
        public EntityDeletingEvent(TEntity entity) : base(entity)
        {
        }
    }
}
namespace DomainEventsSample.Framework.Domain.Events
{
    public class EntityDeletedEvent<TEntity> : EntityDomainEvent<TEntity>
        where TEntity : Entity
    {
        public EntityDeletedEvent(TEntity entity) : base(entity)
        {
        }
    }
}

namespace DomainEventsSample.Framework.Domain.Events
{
    public class EntitySavingEvent<TEntity> : EntityDomainEvent<TEntity>
        where TEntity : Entity
    {
        public EntitySavingEvent(TEntity entity) : base(entity)
        {
        }
    }
}

namespace DomainEventsSample.Framework.Domain.Events
{
    public class EntitySavedEvent<TEntity> : EntityDomainEvent<TEntity>
        where TEntity : Entity
    {
        public EntitySavedEvent(TEntity entity) : base(entity)
        {
        }
    }
}

نکته: برای اسکن کردن تمام هندلرها لازم است کد زیر را به تنظیمات StructureMap اضافه کنید:

Scan(scan =>
{
    scan.ConnectImplementationsToTypesClosing(typeof(IDomainEventHandler<>));
});

public class ProductCreatedEventHandler : IDomainEventHandler<EntityCreatedEvent<Product>>
{
    public bool IsAdvisable => false;

    public void Handle(EntityCreatedEvent<Product> domainEvent)
    {
        //todo: notify users
    }
}

public class ProductApplicationService : IProductApplicationService
{
    private readonly IDomainEventEngine _eventEngine;
    private readonly IUnitOfWork _unitOfWork;
    private readonly IMapper _mapper;

    public ProductApplicationService(IDomainEventEngine eventEngine,IMapper mapper,IUnitOfWork unitOfWork)
    {
        _eventEngine = eventEngine;
        _mapper=mapper;
        _unitOfWork=unitOfWork;
    }

    [Transactional]
    public void Create(ProductCreateViewModel model)
    {
         var entity=_mapper.Map<Product>(model);
        _unitOfWork.Set<Product>().Add(entity);
        _unitOfWork.SaveChanges();
        _eventEngine.Raise(new EntityCreatedEvent<Product>(entity));
    }
}

البته بهتر است برای Raise کردن این نوع رویدادها از مکانیزم Hook استفاده کرد و در زمان ذخیره سازی و فراخوانی متد SaveChange، این عملیات به صورت خودکار صورت گیرند.

در مقاله بعدی با استفاده از Hookها این عملیات را انجام خواهیم داد. 

• شاید امروز معنای یک کد را متوجه شوید، ولی آیا در آینده، مثلا یک سال بعد هم چنین خواهد بود؟
  
•  آیا می‌توانید هر سیستمی را که طراحی می‌کنید، به خاطر بسپارید که فعالیت‌هایش را به چه نحوی انجام می‌دهد؟
  
• اگر در یک کار تیمی باشید، شاید شما متوجه کدتان می‌شوید، ولی آیا تضمینی وجود دارد که دیگران هم متوجه روش شما شوند؟
  
• آیا کدی که شما بر روی آن فکر کرده‌اید و در ذهن خود روش انجام آن را ترسیم کرده‌اید، می‌تواند برای برنامه نویسی که کد شما را می‌بیند هم رخ دهد؟ 
  
• اگر شما به صورت تیمی کاری را انجام دهید و یکی از برنامه نویس‌های شما از تیم جدا شود، چگونه می‌توانید کار او را دنبال کنید؟
• اگر برای برنامه نویسی اتفاق یا حادثه‌ای پیش بیاید که دسترسی شما به او ممکن نباشد چه؟
  

PCMBOAT5.PAS*************************************************************
**
File: PCMBOAT5.PAS
Author: B. Spuida
Date: 1.5.1999
Revision: 
1.1 
PCM-DAS08 and -16S/12 are supported.
Sorting routine inserted.
Set-files are read in and card as well as
amplification factor are parsed.

1.1.1
Standard deviation is calculated.

1.1.2
Median is output. Modal value is output.

1.1.4
Sign in Set-file is evaluated.
Individual values are no longer output.
(For tests with raw data use PCMRAW.EXE)

To do:
outliers routine to be revised.
Statistics routines need reworking.
Existing Datafile is backed up.

Purpose: 
Used for measurement of profiles using the
Water-SP-probes using the amplifier andthe PCM-DAS08-card, values are acquired
with n = 3000. Measurements are taken in 1
second intervals. The values are sorted using
Quicksort and are stacked "raw" as well as after
dismissing the highest and lowest 200 values as
'outliers'.


Requirements:
The Card must have an A/D-converter.
Amplifier and probes must be connected.
Analog Signal must be present.
CB.CFG must be in the directory specified by the
env-Variable "CBDIREC" or in present directory.

// XMLsample.cs
// compile with: /doc:XMLsample.xml
using System;
/// <summary>
/// Class level summary documentation goes here.</summary>
/// <remarks>
/// Longer comments can be associated with a type or member
/// through the remarks tag</remarks>
public class SomeClass
{
    /// <summary>
    /// Store for the name property</summary>
    private string myName = null;

    /// <summary>
    /// The class constructor. </summary>
    public SomeClass()
    {
        // TODO: Add Constructor Logic here
    }

    /// <summary>
    /// Name property </summary>
    /// <value>
    /// A value tag is used to describe the property value</value>
    public string Name
    {
        get
        {
            if (myName == null)
            {
                throw new Exception("Name is null");
            }
            return myName;
        }
    }

    /// <summary>
    /// Description for SomeMethod.</summary>
    /// <param name="s"> Parameter description for s goes here</param>
    /// <seealso cref="String">
    /// You can use the cref attribute on any tag to reference a type or member
    /// and the compiler will check that the reference exists. </seealso>
    public void SomeMethod(string s)
    {
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Data;
using ContosoUniversity.Models;

namespace ContosoUniversity.DAL
{
    public class StudentRepository : IStudentRepository, IDisposable
    {
        private SchoolContext context;

        public StudentRepository(SchoolContext context)
        {
            this.context = context;
        }

        public IEnumerable<Student> GetStudents()
        {
            return context.Students.ToList();
        }

        public Student GetStudentByID(int id)
        {
            return context.Students.Find(id);
        }

        //<snip>
        public void Save()
        {
            context.SaveChanges();
        }
    }
}

public class CustomerRepository : Repository < Customer > {
  public CustomerRepository(DbContext context){
    //a property on the base class
    this.DB = context;
  }

  //base class has Add/Save/Remove/Get/Fetch
}

public class TransactOrderCommand {
  public Customer NewCustomer {get;set;}
  public Customer ExistingCustomer {get;set;}
  public List<Product> Cart {get;set;}
  //all the parameters we need, as properties...
  //...

  //our UnitOfWork
  StoreContext _context;
  public TransactOrderCommand(StoreContext context){
    //allow it to be injected - though that's only for testing
    _context = context;
  }

  public Order Execute(){
    //allow for mocking and passing in... otherwise new it up
    _context = _context ?? new StoreContext();

    //add products to a new order, assign the customer, etc
    //then...
    _context.SubmitChanges();

    return newOrder;
  }
}

using System;
using System.Web.Mvc;

namespace Web.Controllers
{
  public class DataController : Controller
  {
    protected StoreContext _context;

    protected override void OnActionExecuting(ActionExecutingContext filterContext)
    {
      //make sure your DB context is globally accessible
      MyApp.StoreDB = new StoreDB();
    }

    protected override void OnActionExecuted(ActionExecutedContext filterContext)
    {
      MyApp.StoreDB.SubmitChanges();
    }
  }
}

منابع:

• قبلا «مؤلفه 2» ارجاعی را به «مؤلفه 1» داده است؛ لذا امکان ارجاع معکوس را در این حالت، نداریم.
  
• «مؤلفه 1» باید بتواند مستقل از «مؤلفه 2» نیز توزیع شده و کار کند؛ لذا این نیاز برای زمانی است که «مؤلفه 2» برای توزیع در Component Model ما وجود داشته باشد.
  
• نمی‌خواهیم در آینده برای نیازهای مشابه در همان صفحه‌ی X، تغییر جدیدی را در «مؤلفه 1» داشته باشیم (اضافه کردن خصوصیت مورد نظر به مدل نمایشی یا اصطلاحا ویو-مدل متناظر با گرید در در زمان طراحی، جواب مساله نمی‌باشد)
• می‌‌خواهیم به یک طراحی با Loose Coupling (اتصال سست و ضعیف، وابستگی ضعیف) دست پیدا کنیم.

public interface IConvention
{
}

public interface IExtraColumnConvention<T> : IConvention
{
   string Name { get; }
 
   string Title { get; }
 
   void Populate(IEnumerable<T> list);
}

• استفاده از API Reflection موجود در فضای نام System.Reflection 
  
• کلاس TypeDescriptor 

/// <summary>
/// Use this provider when you need access ExtraProperties with TypeDescriptor.GetProperties(instance)
/// </summary>
public class ExtraPropertyTypeDescriptionProvider<T> : TypeDescriptionProvider where T : class
{
    private static readonly TypeDescriptionProvider Default =
        TypeDescriptor.GetProvider(typeof(T));

    public ExtraPropertyTypeDescriptionProvider() : base(Default)
    {
    }

    public override ICustomTypeDescriptor GetTypeDescriptor(Type instanceType, object instance)
    {
        var descriptor = base.GetTypeDescriptor(instanceType, instance);
        return instance == null ? descriptor : new ExtraPropertyCustomTypeDescriptor(descriptor, instance);
    }

    private sealed class ExtraPropertyCustomTypeDescriptor : CustomTypeDescriptor
    {
      //...
    }
}

public class Column4Convention : IExtraColumnConvention<Product>
{
   public string Name => "Column4";
 
   public string Title => "Column 4"
 
   public void Populate(IEnumerable<Product> list)
   {
      //TODO: forEach on list and set ExtraProperty
      // item.ExtraProperty(Name,value)
      // item.ExtraProperty(Name,(obj)=> value)
      // item.ExtraProperty(Name,(obj)=> value, (obj,value)=>)
   }
}

public class Column2Convention : IExtraColumnConvention<Product>
{
   public string Name => "Column2";
 
   public string Title => "Column 2"
 
   public void Populate(IEnumerable<Product> list)
   {
      //TODO: forEach on list and set ExtraProperty
   }
}

public class Column3Convention : IExtraColumnConvention<Product>
{
   public string Name => "Column3";
 
   public string Title => "Column 3"
 
   public void Populate(IEnumerable<Product> list)
   {
      //TODO: forEach on list and set ExtraProperty
   }
}

var products = _productService.PagedList(page:1, pageSize:10);
var columns = _provider.GetServices<IExtraColumnConvention<Product>>();
foreach(var column in columns)
{
  column.Populate(products);
}

پیش زمینه: سیستم عضویت در ASP.NET

[HttpPost]
[AllowAnonymous]
[ValidateAntiForgeryToken]
public async Task<ActionResult> Register(RegisterViewModel model)
{
    if (ModelState.IsValid)
    {
        var user = new ApplicationUser() { UserName = model.UserName };
        var result = await UserManager.CreateAsync(user, model.Password);
        if (result.Succeeded)
        {
            await SignInAsync(user, isPersistent: false);
            return RedirectToAction("Index", "Home");
        }
        else
        {
            AddErrors(result);
        }
    }

    // If we got this far, something failed, redisplay form
    return View(model);
}

[HttpPost]
[AllowAnonymous]
[ValidateAntiForgeryToken]
public async Task<ActionResult> Register(RegisterViewModel model)
{
    if (ModelState.IsValid)
    {
        var user = new ApplicationUser() { UserName = model.UserName };
        var result = await UserManager.CreateAsync(user, model.Password);
        if (result.Succeeded)
        {
            await SignInAsync(user, isPersistent: false);
            return RedirectToAction("Index", "Home");
        }
        else
        {
            AddErrors(result);
        }
    }

    // If we got this far, something failed, redisplay form
    return View(model);
}

private async Task SignInAsync(ApplicationUser user, bool isPersistent)
{
    AuthenticationManager.SignOut(DefaultAuthenticationTypes.ExternalCookie);

    var identity = await UserManager.CreateIdentityAsync(
       user, DefaultAuthenticationTypes.ApplicationCookie);

    AuthenticationManager.SignIn(
       new AuthenticationProperties() { 
          IsPersistent = isPersistent 
       }, identity);
}

// POST: /Account/LogOff
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult LogOff()
{
    AuthenticationManager.SignOut();
    return RedirectToAction("Index", "Home");
}

Button button;
switch (UserSettings.UserSkinType)
{
   case UserSkinTypes.Normal:
      button = new Button();
      break;
   case UserSkinTypes.Fancy:
      button = new FancyButton();
      break;
}

 Button button = ButtonFactory.CreateButton();

 Button button = ServiceLocator.Create(IButton.Class)

Button button = GetTheButton();
Form1 frm = new Form1(button);

 public class UserController
 {        
        protected void OnClickCreate(object sender, EventArgs e)
        {
           // call validation services
           // call create user services
        }
 }

    public class UserWebApiController
    {
        [HttpPost]
        public HttpResponseMessage Create(UserViewModel user)
        {
            // call validation services
            // call create user services
        }
    }

    // سازنده
    public class B
    {
        public static A CreateA(string name, string lastName, string job)
        {
            return new A() {
                Name =name,
                LastName = lastName,
                Job = job
            };
        }
    }
    // ایجاد شونده
    public class A
    {
        public string Name { get; set; }
        public string LastName { get; set; }
        public string Job { get; set; }
    }

    public class Context
    {
        public void Main()
        {
            var name = "Rasoul";
            var lastName = "Abbasi";
            var job = "Developer";            
            var obj = B.CreateA(name, lastName, job);
        }
    }

    class Controller
    {
        public void CreateProduct(string name, int categoryId) { }
        public void EditProduct(int id, string name) { }
        public void DeleteProduct(int id) { }
        public void CreateCategory(string name) { }
        public void EditCategory(int id, string name) { }
        public void DeleteCategory(int id) { }
    }  

    class SenderA
    {
        public Mediator mediator { get; }
        public SenderA() { mediator = new Mediator(); }
        public void Send(string message, string reciever) { mediator.Send(message, reciever); }
    }
    class SenderB
    {
        public Mediator mediator { get; }
        public SenderB() { mediator = new Mediator(); }
        public void Send(string message) { }
    }

    public class RecieverA
    {
        public void DoAction(string message)
        {
            // انجام عملیات بر اساس پیغام دریافت شده
            switch (message)
            {
                case "create":
                    break;
                case "delete":
                    break;
                default:
                    break;
            }
        }
    }
    public class RecieverB
    {
        public void DoAction(string message)
        {
            // انجام عملیات بر اساس پیغام دریافت شده
            switch (message)
            {
                case "edit":
                    break;
                case "rollback":
                    break;
                default:
                    break;
            }
        }
    }
    class Mediator
    {
        internal void Send(string message, string reciever)
        {
            switch (reciever)
            {
                case "A":
                    var recieverObjA = new RecieverA();
                    recieverObjA.DoAction(message);
                    break;
                case "B":
                    var recieverObjB = new RecieverB();
                    recieverObjB.DoAction(message);
                    break;

                default:
                    break;
            }
        }
    }
    class IndirectionContext
    {
        public void Main()
        {
            var senderA = new SenderA();
            senderA.Send("rollback", "B");
            var senderB = new SenderA();
            senderB.Send("create", "A");

        }
    }