var unicorn = {
   legs: 4,
   color: 'brown',
   horn: true
};

var proxyUnicorn = new Proxy(unicorn, {
      get: function(target, property) {
            if(property === 'color') {
                  return 'awesome ' + target[property];
              } else {
                  return target[property];
           }
      }
});

var proxyUnicorn = new Proxy(unicorn, {
           set: function(target, property, value) {
                    if(property === 'horn' && value === false) {
                         console.log('unicorn cannot ever lose its horn!');
                      } else {
                         target[property] = value;
                      }
           }
});

var unicorn = {
   legs: 4,
   color: 'brown',
   horn: true,
   hornAttack: function(target) {
        return target.name + ' was obliterated!';
   }
};

unicorn.hornAttack = new Proxy(unicorn.hornAttack, {
        apply: function(target, context, args) {
                  if(context !== unicorn) {
                     return 'nobody can use unicorn horn but unicorn!';
                   } else {
                     return target.apply(context, args);
                 }
        }
});

Lazy<ExpensiveResource> ownedResource = new Lazy<ExpensiveResource>();

public Lazy(bool isThreadSafe);
public Lazy(Func<T> valueFactory, bool isThreadSafe);

using System;
using System.Threading;

namespace LazyExample
{
 class Program
 {
     static void Main()
     {
         Console.WriteLine("Before assignment");
         var slow = new Lazy<Slow>();
         Console.WriteLine("After assignment");

         Thread.Sleep(1000);

         Console.WriteLine(slow);
         Console.WriteLine(slow.Value);

         Console.WriteLine("Press a key...");
         Console.Read();
     }
 }


 class Slow
 {
     public Slow()
     {
         Console.WriteLine("Start creation");
         Thread.Sleep(2000);
         Console.WriteLine("End creation");
     }
 }
}

Before assignment
After assignment
Value is not created.
Start creation
End creation
LazyExample.Slow
Press a key...

using System;

namespace LazySample
{
 class Program
 {
     static void Main()
     {
         var expensiveClass =
             new Lazy<ExpensiveClass>
             (
                 () =>
                 {
                     var fobj = new ExpensiveClass
                                    {
                         SomeProperty = 100
                     };
                     return fobj;
                 }
             );

         Console.WriteLine("expensiveClass has value yet {0}",
             expensiveClass.IsValueCreated);

         Console.WriteLine("expensiveClass.SomeProperty value {0}",
             (expensiveClass.Value).SomeProperty);

         Console.WriteLine("expensiveClass has value yet {0}",
             expensiveClass.IsValueCreated);

         Console.WriteLine("Press a key...");
         Console.Read();
     }
 }

 class ExpensiveClass
 {
     public int SomeProperty { get; set; }

     public ExpensiveClass()
     {
         Console.WriteLine("ExpensiveClass constructed");
     }
 }
}

public abstract class Observer
    {
        protected Observable Observable;
        public abstract void Update();
    }

 public  class Observable
    {
        private readonly List<Observer> _observers = new List<Observer>();

        public void Attach(Observer observer)
        {
            _observers.Add(observer);
        }
        public void Dettach(Observer observer)
        {
            _observers.Remove(observer);
        }

        public void NotifyAllObservers()
        {
            foreach (var observer in _observers)
            {
                observer.Update();
            }
        }
    }

 public  class Switch:Observable
    {
        private bool _state;

        public bool ChangeState
        {
            set
            {
                _state = value;
                NotifyAllObservers();
            }
            get { return _state; }
        }
    }

   public class RedLED:Observer
    {
        private bool _on = false;
        public override void Update()
        {
            _on = !_on;
            Console.WriteLine($"Red LED is {((_on) ? "On" : "Off")}");
        }
    }

  public class GreenLED:Observer
    {
        private bool _on = false;
        public override void Update()
        {
            _on = !_on;
            Console.WriteLine($"Green LED is {((_on) ? "On" : "Off")}");
        }
    }

  public  class BlueLED:Observer
    {
        private bool _on = false;
        public override void Update()
        {
            _on = !_on;
            Console.WriteLine($"Blue LED is {((_on) ? "On" : "Off")}");
        }
    }

var greenLed=new GreenLED();
            var redLed=new RedLED();
            var blueLed=new BlueLED();

            var switchKey=new Switch();
            switchKey.Attach(greenLed);
            switchKey.Attach(redLed);
            switchKey.Attach(blueLed);

            switchKey.ChangeState = true;
            switchKey.ChangeState = false;

Green LED is On
Red LED is On
Blue LED is On
Green LED is Off
Red LED is Off
Blue LED is Off

  public class ImageManagement
  {
      public string GetImageForTimeOfDay()
      {
          int currentHour = DateTime.Now.Hour;
          return currentHour > 6 && currentHour < 21 ? "sun.jpg" : "moon.jpg";
      }

  }

using System;
using NUnit.Framework;

  [TestFixture]
  public class CMyTest
  {
      [Test]
      public void DaytimeTest()
      {
          int currentHour = DateTime.Now.Hour;

          if (currentHour > 6 && currentHour < 21)
          {
              const string expectedImagePath = "sun.jpg";
              ImageManagement image = new ImageManagement();
              string path = image.GetImageForTimeOfDay();
              Assert.AreEqual(expectedImagePath, path);
          }
          else
          {
              Assert.Ignore("تنها در طول روز قابل بررسی است");
          }
      }

      [Test]
      public void NighttimeTest()
      {
          int currentHour = DateTime.Now.Hour;

          if (currentHour < 6 || currentHour > 21)
          {
              const string expectedImagePath = "moon.jpg";
              ImageManagement image = new ImageManagement();
              string path = image.GetImageForTimeOfDay();
              Assert.AreEqual(expectedImagePath, path);
          }
          else
          {
              Assert.Ignore("تنها در طول شب قابل بررسی است");
          }
      }

  }

using NUnit.Framework;
using Rhino.Mocks;

namespace testWinForms87
{
  public interface IDateTime
  {
      int GetHour();
  }

  public class ImageManagement
  {
      public string GetImageForTimeOfDay(IDateTime time)
      {
          int currentHour = time.GetHour();

          return currentHour > 6 && currentHour < 21 ? "sun.jpg" : "moon.jpg";
      }
  }

  [TestFixture]
  public class CMocking
  {
      [Test]
      public void DaytimeTest()
      {
          MockRepository mocks = new MockRepository();
          IDateTime timeController = mocks.CreateMock<IDateTime>();

          using (mocks.Record())
          {
              Expect.Call(timeController.GetHour()).Return(15);
          }

          using (mocks.Playback())
          {
              const string expectedImagePath = "sun.jpg";
              ImageManagement image = new ImageManagement();
              string path = image.GetImageForTimeOfDay(timeController);
              Assert.AreEqual(expectedImagePath, path);
          }
      }

      [Test]
      public void NighttimeTest()
      {
          MockRepository mocks = new MockRepository();
          IDateTime timeController = mocks.CreateMock<IDateTime>();
          using (mocks.Record())
          {
              Expect.Call(timeController.GetHour()).Return(1);
          }

          using (mocks.Playback())
          {
              const string expectedImagePath = "moon.jpg";
              ImageManagement image = new ImageManagement();
              string path = image.GetImageForTimeOfDay(timeController);
              Assert.AreEqual(expectedImagePath, path);
          }
      }
  }

}

MockRepository mocks = new MockRepository();

IDateTime timeController = mocks.CreateMock<IDateTime>();
using (mocks.Record())
{
 Expect.Call(timeController.GetHour()).Return(15);

}

using (mocks.Playback())
{
 string expectedImagePath = "sun.jpg";
 ImageManagement image = new ImageManagement();
 string path = image.GetImageForTimeOfDay(timeController);
 Assert.AreEqual(expectedImagePath, path);

}

public class DateTimeController : IDateTime
{
  public int GetHour()
  {
     return DateTime.Now.Hour;
  }
}

namespace MvcApplication6.Models
{
    public class Account
    {
        public string Name { get; set; }
        public string Password { get; set; }
    }
}

using System.Web.Mvc;
using MvcApplication6.Models;

namespace MvcApplication6.Controllers
{
    public class LoginController : Controller
    {
        [HttpGet]
        public ActionResult Index()
        {
            return View(); //Shows the login page
        }

        [HttpPost]
        public ActionResult LoginResult()
        {
            string name = Request.Form["name"];
            string password = Request.Form["password"];

            if (name == "Vahid" && password == "123")
                ViewBag.Message = "Succeeded";
            else
                ViewBag.Message = "Failed";

            return View("Result");
        }

        [HttpPost]
        [ActionName("LoginResultWithParams")]
        public ActionResult LoginResult(string name, string password)
        {
            if (name == "Vahid" && password == "123")
                ViewBag.Message = "Succeeded";
            else
                ViewBag.Message = "Failed";

            return View("Result");
        }

        [HttpPost]
        public ActionResult Login(Account account)
        {
            if (account.Name == "Vahid" && account.Password == "123")
                ViewBag.Message = "Succeeded";
            else
                ViewBag.Message = "Failed";

            return View("Result");
        }
    }
}

@model MvcApplication6.Models.Account
@{
    ViewBag.Title = "Index";
}
<h2>
    Login</h2>
@using (Html.BeginForm(actionName: "LoginResult", controllerName: "Login"))
{
    <fieldset>
        <legend>Test LoginResult()</legend>
        <p>
            Name: @Html.TextBoxFor(m => m.Name)</p>
        <p>
            Password: @Html.PasswordFor(m => m.Password)</p>
        <input type="submit" value="Login" />
    </fieldset>
}
@using (Html.BeginForm(actionName: "LoginResultWithParams", controllerName: "Login"))
{
    <fieldset>
        <legend>Test LoginResult(string name, string password)</legend>
        <p>
            Name: @Html.TextBoxFor(m => m.Name)</p>
        <p>
            Password: @Html.PasswordFor(m => m.Password)</p>
        <input type="submit" value="Login" />
    </fieldset>
}
@using (Html.BeginForm(actionName: "Login", controllerName: "Login"))
{
    <fieldset>
        <legend>Test Login(Account acc)</legend>
        <p>
            Name: @Html.TextBoxFor(m => m.Name)</p>
        <p>
            Password: @Html.PasswordFor(m => m.Password)</p>
        <input type="submit" value="Login" />
    </fieldset>
}

@{
    ViewBag.Title = "Result";
}
<fieldset>
    <legend>Login Result</legend>
    <p>
        @ViewBag.Message</p>
</fieldset>

<form action="/Login/LoginResult" method="post">   
    <fieldset>
        <legend>Test LoginResult()</legend>
        <p>
            Name: <input id="Name" name="Name" type="text" value="" /></p>
        <p>
            Password: <input id="Password" name="Password" type="password" /></p>
        <input type="submit" value="Login" />
    </fieldset>
</form>

[AcceptVerbs(HttpVerbs.Get)]

The current request for action 'LoginResult' on controller type 'LoginController' is ambiguous between the following action methods:
System.Web.Mvc.ActionResult LoginResult() on type MvcApplication6.Controllers.LoginController
System.Web.Mvc.ActionResult LoginResult(System.String, System.String) on type MvcApplication6.Controllers.LoginController

public HttpContextBase HttpContext { get; }
public HttpRequestBase Request { get; }
public HttpResponseBase Response { get; }
public RouteData RouteData { get; }

public virtual NameValueCollection QueryString { get; } // GET variables
public NameValueCollection Form { get; } // POST variables
public HttpCookieCollection Cookies { get; }
public NameValueCollection Headers { get; }
public string HttpMethod { get; }

Request.Form
Request.QueryString
Request.Files
RouteData.Values

[HttpPost]
[ActionName("LoginResultWithFormCollection")]
public ActionResult LoginResult(FormCollection collection)
{
       string name = collection["name"];
       string password = collection["password"];

       if (name == "Vahid" && password == "123")
                ViewBag.Message = "Succeeded";
       else
                ViewBag.Message = "Failed";

       return View("Result");
}

[HttpPost]
public ActionResult LoginResultUpdateFormCollection(FormCollection collection)
{
       var account = new Account();
       this.UpdateModel(account, collection.ToValueProvider());

       if (account.Name == "Vahid" && account.Password == "123")
                ViewBag.Message = "Succeeded";
       else
                ViewBag.Message = "Failed";

       return View("Result");
}

[HttpPost]
public ActionResult LoginResultUpdateModel()
{
       var account = new Account();
        this.UpdateModel(account);

        if (account.Name == "Vahid" && account.Password == "123")
                ViewBag.Message = "Succeeded";
        else
                ViewBag.Message = "Failed";

        return View("Result");
}

username=vahid&password=1234

 { path: 'component-one/:id', component: Component1Component,canActivate:[LoginGuard]}

 { path: 'component-one/:id', component: Component1Component,canActivate:[LoginGuard,SecondGuard]}

 { path: 'component-one/:id', component: Component1Component,canActivate:[LoginGuard,SecondGuard] }