public class MyDbContextBase : DbContext, IUnitOfWork

public void ConfigureServices(IServiceCollection services)
{
   services.AddMvc();
   services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
}

public IActionResult ProcessForm()
{
   HttpContext.Items["firstname"] = "Vahid";
   HttpContext.Items["lastname"] = "N.";
   return View();
}

public class MyHelperClass
{
    private readonly IHttpContextAccessor _contextAccessor;
    public MyHelperClass(IHttpContextAccessor  contextAccessor)
    {
        _contextAccessor = contextAccessor;
    }

    public string DoWork()
    {
        string firstName = _contextAccessor.HttpContext.Items["firstname"].ToString();
        string lastName = _contextAccessor.HttpContext.Items["lastname"].ToString();
        return $"Hello {firstName} {lastName}!";
    }
}

Environment.NewLine

Console.WriteLine( "NewLine: {0}first line{0}second line{0}third line", Environment.NewLine );

ExceptionDispatchInfo possibleException = null;
try
{
    int.Parse( "a" );
}
catch ( FormatException ex )
{
    possibleException = ExceptionDispatchInfo.Capture( ex );
}
possibleException?.Throw();

Debug.Assert(1 == 0, "عدد 1 برابر با 0 نیست");

Debug.WriteIf( 1 == 1, "display message in output window :D" );

Debug.WriteLine("تست تورفتگی");
Debug.Indent();
Debug.WriteLine("یک واحد افزایش داده شد");
Debug.Unindent();
Debug.WriteLine("یک واحد کاهش داده شد");
Debug.WriteLine("پایان تست");

<?xml version="1.0" encoding="UTF-8" ? />
<OpenSearchDescription xmlns="http://a9.com/-/spec/opensearch/1.1/">
    <ShortName>My Site's Asset Finder</ShortName>
    <Description>Find all your assets</Description>
    <Url type="text/html"
        method="get"
        template="http://MySite.com/Home/Search/?q=searchTerms"/>
    <InputEncoding>UTF-8</InputEncoding>
    <SearchForm>http://MySite.com/</SearchForm>
</OpenSearchDescription>

using System;
using System.Text;
using System.Web;
using System.Web.Mvc;
using System.Xml;

namespace WebToolkit
{
    public class OpenSearchResult : ActionResult
    {
        public string ShortName { set; get; }
        public string Description { set; get; }
        public string SearchForm { set; get; }
        public string FavIconUrl { set; get; }
        public string SearchUrlTemplate { set; get; }

        public override void ExecuteResult(ControllerContext context)
        {
            if (context == null)
                throw new ArgumentNullException("context");

            var response = context.HttpContext.Response;
            writeToResponse(response);
        }

        private void writeToResponse(HttpResponseBase response)
        {
            response.ContentEncoding = Encoding.UTF8;
            response.ContentType = "application/opensearchdescription+xml";
            using (var xmlWriter = XmlWriter.Create(response.Output, new XmlWriterSettings { Indent = true }))
            {
                xmlWriter.WriteStartElement("OpenSearchDescription", "http://a9.com/-/spec/opensearch/1.1/");

                xmlWriter.WriteElementString("ShortName", ShortName);
                xmlWriter.WriteElementString("Description", Description);
                xmlWriter.WriteElementString("InputEncoding", "UTF-8");
                xmlWriter.WriteElementString("SearchForm", SearchForm);

                xmlWriter.WriteStartElement("Url");
                xmlWriter.WriteAttributeString("type", "text/html");
                xmlWriter.WriteAttributeString("template", SearchUrlTemplate);                
                xmlWriter.WriteEndElement();

                xmlWriter.WriteStartElement("Image");
                xmlWriter.WriteAttributeString("width", "16");
                xmlWriter.WriteAttributeString("height", "16");
                xmlWriter.WriteString(FavIconUrl);
                xmlWriter.WriteEndElement();

                xmlWriter.WriteEndElement();
                xmlWriter.Close();
            }
        }
    }
}

using System.Web.Mvc;

namespace Readers
{
    public partial class OpenSearchController : Controller
    {
        public virtual ActionResult Index()
        {
            var fullBaseUrl = Url.Action(result: MVC.Home.Index(), protocol: "http");
            return new OpenSearchResult
            {
                ShortName = ".NET Tips",
                Description = ".NET Tips Contents Search",
                SearchForm = fullBaseUrl,
                FavIconUrl = fullBaseUrl + "favicon.ico",
                SearchUrlTemplate = Url.Action(result: MVC.Search.Index(), protocol: "http") + "?term={searchTerms}"
            };
        }
    }
}

<link href="@Url.Action(result: MVC.OpenSearch.Index(), protocol: "http")" rel="search"
        title=".NET Tips Search"  type="application/opensearchdescription+xml" />

    public interface ITaskService
    {
        void Run();
    }

    public class MyTaskService : ITaskService
    {
        public void Run()
        {
            throw new InvalidOperationException("An exception from the MyTaskService!");
        }
    }

using System;
using Microsoft.Extensions.Logging;
namespace CoreIocServices
{
    public class MyTaskServiceDecorator : ITaskService
    {
        private readonly ILogger<MyTaskServiceDecorator> _logger;
        private readonly ITaskService _decorated;

        public MyTaskServiceDecorator(
            ILogger<MyTaskServiceDecorator> logger,
            ITaskService decorated)
        {
            _logger = logger;
            _decorated = decorated;
        }

        public void Run()
        {
            try
            {
                _decorated.Run();
            }
            catch (Exception ex)
            {
                _logger.LogCritical(ex, "An unhandled exception has been occurred.");
            }
        }
    }
}

namespace CoreIocSample02
{
    public class Startup
    {
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddTransient<MyTaskService>();
            services.AddTransient<ITaskService>(serviceProvider =>
                new MyTaskServiceDecorator(
                     serviceProvider.GetService<ILogger<MyTaskServiceDecorator>>(),
                     serviceProvider.GetService<MyTaskService>())
            );

namespace CoreIocSample02
{
    public class Startup
    {
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddTransient<ITaskService, MyTaskService>();
            services.Decorate<ITaskService, MyTaskServiceDecorator>();

هدف اصلی از طراحی نرم افزار، غالب شدن بر پیچیدگی‌ها می‌باشد. اصل CQS متد‌ها را به دو دسته‌ی Command و Query تقسیم می‌کند که Query ، اطلاعاتی را از وضعیت سیستم بر می‌گرداند، ولی command  وضعیت سیستم را تغییر می‌دهد و مهمترین دستاورد CQS ما را به سمت کدی تمیز‌تر و با قابلیت درک بهتر می‌رساند.