@section Scripts
{
    <script type="text/javascript">
    $(document).ready(function () {
        $('#list').jqGrid({
            caption: "آزمایش ششم",
                 // مانند قبل
            }).navGrid(
                 // مانند قبل
                    }).jqGrid('navButtonAdd', '#pager', {
                        caption: "", buttonicon: "ui-icon-print", title: "خروجی پی دی اف",
                        onClickButton: function () {
                            $("#list").jqGrid('excelExport', { url: '@Url.Action("GetProducts", "Home")' });
                        }
                    });
        });
    </script>
}

public ActionResult GetProducts(string sidx, string sord, int page, int rows,
                                             bool _search, string searchField, string searchString,
                                             string searchOper, string filters, string oper)

namespace jqGrid06.Models
{
    public class JqGridRequest
    {
        public string sidx { set; get; }
        public string sord { set; get; }
        public int page { set; get; }
        public int rows { set; get; }
        public bool _search { set; get; }
        public string searchField { set; get; }
        public string searchString { set; get; }
        public string searchOper { set; get; }
        public string filters { set; get; }
        public string oper { set; get; }
    }
}

        public ActionResult GetProducts(JqGridRequest request)
        {
            var list = ProductDataSource.LatestProducts;

            var pageIndex = request.page - 1;
            var pageSize = request.rows;
            var totalRecords = list.Count;
            var totalPages = (int)Math.Ceiling(totalRecords / (float)pageSize);

            var productsQuery = list.AsQueryable();

            productsQuery = new JqGridSearch().ApplyFilter(productsQuery, request, this.Request.Form);
            productsQuery = productsQuery.OrderBy(request.sidx + " " + request.sord);

            if (string.IsNullOrWhiteSpace(request.oper))
            {
                productsQuery = productsQuery
                                    .Skip(pageIndex * pageSize)
                                    .Take(pageSize);
            }
            else if (request.oper == "excel")
            {
                productsQuery = productsQuery
                                    .Skip(pageIndex * pageSize);
            }

            var productsList = productsQuery.ToList();

            if (!string.IsNullOrWhiteSpace(request.oper) && request.oper == "excel")
            {
                new ProductsPdfReport().CreatePdfReport(productsList);
            }

            var productsData = new JqGridData
            {
                Total = totalPages,
                Page = request.page,
                Records = totalRecords,
                Rows = (productsList.Select(product => new JqGridRowData
                {
                    Id = product.Id,
                    RowCells = new List<string>
                    {
                        product.Id.ToString(CultureInfo.InvariantCulture),
                        product.Name,
                        product.AddDate.ToPersianDate(),
                        product.Price.ToString(CultureInfo.InvariantCulture)
                    }
                })).ToArray()
            };

            return Json(productsData, JsonRequestBehavior.AllowGet);
        }

public class Book
    {
        private int code = 10;        

        public int GetCode()
        {
            return code;
        }
    }

public class Book
    {
        private readonly int code = 10;        

        public int GetCode()
        {
            return code = 20;
        }        
    }

using System.Reflection;

 public class Book
 {
        private int code = 10;
 }

 public class Program
 {
        static void Main( string[] args )
        {
            Book book = new Book();
            var codeField = book.GetType().GetField( "code", BindingFlags.NonPublic | BindingFlags.Instance );
            codeField.SetValue( book, 20 );
            var value = codeField.GetValue( book );
        }
    }

using System.Reflection;

 public class Book
 {
        private readonly int code = 10;
 }

 public class Program
 {
        static void Main( string[] args )
        {
            Book book = new Book();
            var codeField = book.GetType().GetField( "code", BindingFlags.NonPublic | BindingFlags.Instance );
            codeField.SetValue( book, 50);
            var value = codeField.GetValue( book );
        }
    }

public class Comment
{
    public int Id { get; set; }
    public string CommentText { get; set; }
    public string User { get; set; }
    
    public virtual ICollection<ArticleComment> ArticleComments { get; set; }
    public virtual ICollection<VideoComment> VideoComments { get; set; }
    public virtual ICollection<EventComment> EventComments { get; set; }
}

public class Article
{
    public Article()
    {
        ArticleComments = new HashSet<ArticleComment>();
    }
    
    public int Id { get; set; }
    public string Title { get; set; }
    public string Slug { get; set; }
    public string Description { get; set; }
    
    public virtual ICollection<ArticleComment> ArticleComments { get; set; }

}

public class Video
{
    public Video()
    {
        VideoComments = new HashSet<VideoComment>();
    }
    
    public int Id { get; set; }
    public string Url { get; set; }
    public string Description { get; set; }
    
    public virtual ICollection<VideoComment> VideoComments { get; set; }
}

public class Event
{
    public Event()
    {
        EventComments = new HashSet<EventComment>();
    }
    
    public int Id { get; set; }
    public string Name { get; set; }
    public DateTimeOffset? Start { get; set; }
    public DateTimeOffset? End { get; set; }
    
    public virtual ICollection<EventComment> EventComments { get; set; }
}

public class MyDbContext : DbContext
{
    public DbSet<Article> Articles { get; set; }
    public DbSet<ArticleComment> ArticleComments { get; set; }
    public DbSet<Video> Videos { get; set; }
    public DbSet<VideoComment> VideoComments { get; set; }
    public DbSet<Event> Events { get; set; }
    public DbSet<EventComment> EventComments { get; set; }
    public DbSet<Comment> Comments { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder options)
        => options.UseSqlite("Data Source=polymorphic.db");

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<ArticleComment>(entity =>
        {
            entity.HasKey(e => new { e.CommentId, e.ArticleId })
                .HasName("PK_dbo.ArticleComments");

            entity.HasIndex(e => e.ArticleId)
                .HasName("IX_ArticleId");

            entity.HasIndex(e => e.CommentId)
                .HasName("IX_ArticleCommentId");

            entity.HasOne(d => d.Article)
                .WithMany(p => p.ArticleComments)
                .HasForeignKey(d => d.ArticleId)
                .HasConstraintName("FK_dbo.ArticleComments_dbo.Articles_ArticleId");

            entity.HasOne(d => d.Comment)
                .WithMany(p => p.ArticleComments)
                .HasForeignKey(d => d.CommentId)
                .HasConstraintName("FK_dbo.ArticleComments_dbo.Comments_CommentId");
        });
        
        modelBuilder.Entity<VideoComment>(entity =>
        {
            entity.HasKey(e => new { e.CommentId, e.VideoId })
                .HasName("PK_dbo.VideoComments");

            entity.HasIndex(e => e.VideoId)
                .HasName("IX_VideoId");

            entity.HasIndex(e => e.CommentId)
                .HasName("IX_VideoCommentId");

            entity.HasOne(d => d.Video)
                .WithMany(p => p.VideoComments)
                .HasForeignKey(d => d.VideoId)
                .HasConstraintName("FK_dbo.VideoComments_dbo.Videos_VideoId");

            entity.HasOne(d => d.Comment)
                .WithMany(p => p.VideoComments)
                .HasForeignKey(d => d.CommentId)
                .HasConstraintName("FK_dbo.VideoComments_dbo.Comments_CommentId");
        });
        
        modelBuilder.Entity<EventComment>(entity =>
        {
            entity.HasKey(e => new { e.CommentId, e.EventId })
                .HasName("PK_dbo.EventComments");

            entity.HasIndex(e => e.EventId)
                .HasName("IX_EventId");

            entity.HasIndex(e => e.CommentId)
                .HasName("IX_EventCommentId");

            entity.HasOne(d => d.Event)
                .WithMany(p => p.EventComments)
                .HasForeignKey(d => d.EventId)
                .HasConstraintName("FK_dbo.EventComments_dbo.Events_EventId");

            entity.HasOne(d => d.Comment)
                .WithMany(p => p.EventComments)
                .HasForeignKey(d => d.CommentId)
                .HasConstraintName("FK_dbo.EventComments_dbo.Comments_CommentId");
        });
    }
}

namespace jQueryMvcSample03.Models
{
    public class BlogPost
    {
        public int Id { set; get; }
        public string Title { set; get; }
        public string Body { set; get; }

        /// <summary>
        /// اطلاعات رای گیری یک مطلب به صورت یک خاصیت تو در تو یا پیچیده
        /// </summary>
        public Rating Rating { set; get; }

        public BlogPost()
        {
            Rating = new Rating();
        }
    }
}

namespace jQueryMvcSample03.Models
{
    //[ComplexType]
    public class Rating
    {
        public double? TotalRating { get; set; }
        public int? TotalRaters { get; set; }
        public double? AverageRating { get; set; }
    }
}

using System.Collections.Generic;
using System.Linq;
using jQueryMvcSample03.Models;

namespace jQueryMvcSample03.DataSource
{
    /// <summary>
    /// منبع داده فرضی
    /// </summary>
    public static class BlogPostDataSource
    {
        private static IList<BlogPost> _cachedItems;
        /// <summary>
        /// با توجه به استاتیک بودن سازنده کلاس، تهیه کش، پیش از سایر فراخوانی‌ها صورت خواهد گرفت
        /// باید دقت داشت که این فقط یک مثال است و چنین کشی به معنای
        /// تهیه یک لیست برای تمام کاربران سایت است
        /// </summary>
        static BlogPostDataSource()
        {
            _cachedItems = createBlogPostsInMemoryDataSource();
        }

        /// <summary>
        /// هدف صرفا تهیه یک منبع داده آزمایشی ساده تشکیل شده در حافظه است
        /// </summary>        
        private static IList<BlogPost> createBlogPostsInMemoryDataSource()
        {
            var results = new List<BlogPost>();
            for (int i = 1; i < 30; i++)
            {
                results.Add(new BlogPost { Id = i, Title = "عنوان " + i, Body = "متن ... متن ... متن " + i, Rating = new Rating { TotalRaters = i + 1, AverageRating = 3.5 } });
            }
            return results;
        }

        /// <summary>
        /// پارامترهای شماره صفحه و تعداد رکورد به ازای یک صفحه برای صفحه بندی نیاز هستند
        /// شماره صفحه از یک شروع می‌شود
        /// </summary>
        public static IList<BlogPost> GetLatestBlogPosts(int pageNumber, int recordsPerPage = 4)
        {
            var skipRecords = pageNumber * recordsPerPage;
            return _cachedItems
                        .OrderByDescending(x => x.Id)
                        .Skip(skipRecords)
                        .Take(recordsPerPage)
                        .ToList();
        }
    }
}

/* star rating system */
.post_rating
{
direction: ltr;
}
.rating
{
text-indent: -99999px;
overflow: hidden;
background-repeat: no-repeat;
display: inline-block;
width: 8px;
height: 16px;
}
.rating.stars
{
background-image: url('Images/star_rating.png');
}
.rating.stars.active
{
cursor: pointer;
}
.star-left_off
{
background-position: -0px -0px;
}
.star-left_on
{
background-position: -16px -0px;
}
.star-right_off
{
background-position: -8px -0px;
}
.star-right_on
{
background-position: -24px -0px;
}

// <![CDATA[
(function ($) {
    $.fn.StarRating = function (options) {
        var defaults = {            
            ratingStarsSpan: '.rating.stars',
            postInfoUrl: '/',
            loginUrl: '/login',
            errorHandler: null,
            completeHandler: null,
            onlyOneTimeHandler: null
        };
        var options = $.extend(defaults, options);

        return this.each(function () {
            var ratingStars = $(this);

            $(ratingStars).unbind('mouseover');
            $(ratingStars).mouseover(function () {
                var span = $(this).parent("span");
                var newRating = $(this).attr("value");
                setRating(span, newRating);
            });

            $(ratingStars).unbind('mouseout');
            $(ratingStars).mouseout(function () {
                var span = $(this).parent("span");
                var rating = span.attr("rating");
                setRating(span, rating);
            });

            $(ratingStars).unbind('click');
            $(ratingStars).click(function () {
                var span = $(this).parent("span");
                var newRating = $(this).attr("value");
                var text = span.children("span");
                var pID = span.attr("post");
                var type = span.attr("sectiontype");
                postData({ postID: pID, rating: newRating, sectionType: type });
                span.attr("rating", newRating);
                setRating(span, newRating);
            });

            function setRating(span, rating) {
                span.find(options.ratingStarsSpan).each(function () {
                    var value = parseFloat($(this).attr("value"));
                    var imgSrc = $(this).attr("class");
                    if (value <= rating)
                        $(this).attr("class", imgSrc.replace("_off", "_on"));
                    else
                        $(this).attr("class", imgSrc.replace("_on", "_off"));
                });
            }

            function postData(dataJsonArray) {
                $.ajax({
                    type: "POST",
                    url: options.postInfoUrl,
                    data: JSON.stringify(dataJsonArray),
                    contentType: "application/json; charset=utf-8",
                    dataType: "json",
                    complete: function (xhr, status) {
                        var data = xhr.responseText;
                        if (xhr.status == 403) {
                            window.location = options.loginUrl;
                        }
                        else if (status === 'error' || !data) {
                            if (options.errorHandler)
                                options.errorHandler(this);
                        }
                        else if (data == "nok") {
                            if (options.onlyOneTimeHandler)
                                options.onlyOneTimeHandler(this);
                        }
                        else {
                            if (options.completeHandler)
                                options.completeHandler(this);
                        }
                    }
                });
            }
        });
    };
})(jQuery);
// ]]>

 { postID: pID, rating: newRating, sectionType: type }

<head>
    <title>@ViewBag.Title</title>    
    <link href="@Url.Content("Content/starRating.css")" rel="stylesheet" type="text/css" />
    <link href="@Url.Content("Content/Site.css")" rel="stylesheet" type="text/css" />
    <script src="@Url.Content("~/Scripts/jquery-1.9.1.min.js")" type="text/javascript"></script>
    <script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script>
    <script src="@Url.Content("~/Scripts/jquery.unobtrusive-ajax.min.js")" type="text/javascript"></script>
    <script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script>
    <script src="@Url.Content("~/Scripts/jquery.StarRating.js")" type="text/javascript"></script>
    @RenderSection("JavaScript", required: false)
</head>

@using System.Globalization
@helper AddStarRating(int postId,
                      double? average = 0, int? postRatingsCount = 0, string type = "BlogPost",
                      string tooltip = "لطفا جهت رای دادن کلیک نمائید")
    {
        string actIt = "active ";
        if (!average.HasValue) { average = 0; }
        if (!postRatingsCount.HasValue) { postRatingsCount = 0; }
    
    <span class='postRating' rating='@average' post='@postId' title='@tooltip' sectiontype='@type'>
        @for (double i = .5; i <= 5.0; i = i + .5)
        {
            string left;
            if (i <= average)
            {
                left = (i * 2) % 2 == 1 ? "left_on" : "right_on";
            }
            else
            {
                left = (i * 2) % 2 == 1 ? "left_off" : "right_off";
            }
            <span class='rating stars @(actIt)star-@left' value='@i'></span>
        }
        &nbsp;
        @if (postRatingsCount > 0)
        {
            var ratingInfo = string.Format(CultureInfo.InvariantCulture, "امتیاز {0:0.00} از 5 توسط {1} نفر", average, postRatingsCount);
            <span>@ratingInfo</span>                
        }
        else
        {
            <span></span>
        }
    </span>
}

using System.Web.Mvc;
using System.Web.UI;
using jQueryMvcSample03.DataSource;
using jQueryMvcSample03.Security;

namespace jQueryMvcSample03.Controllers
{
    public class HomeController : Controller
    {
        public ActionResult Index()
        {
            var postsList = BlogPostDataSource.GetLatestBlogPosts(pageNumber: 0);
            return View(postsList); //نمایش صفحه اصلی
        }


        [HttpPost]
        [AjaxOnly]
        [OutputCache(Location = OutputCacheLocation.None, NoStore = true)]
        public ActionResult SaveRatings(int? postId, double? rating, string sectionType)
        {
            if (postId == null || rating == null || string.IsNullOrWhiteSpace(sectionType))
                return Content(null); //اعلام بروز خطا

            if (!this.HttpContext.CanUserVoteBasedOnCookies(postId.Value, sectionType))
                return Content("nok"); //اعلام فقط یکبار مجاز هستید رای دهید

            switch (sectionType) //قسمت‌های مختلف سایت که در جداول مختلفی قرار دارند نیز می‌توانند گزینه امتیاز دهی داشته باشند
            {
                case "BlogPost":
                    //الان شماره مطلب و رای ارسالی را داریم که می‌توان نسبت به ذخیره آن اقدام کرد
                    //مثلا
                    //_blogPostsService.SaveRating(postId.Value, rating.Value);
                    break;

                //... سایر قسمت‌های دیگر سایت

                default:
                    return Content(null); //اعلام بروز خطا
            }

            return Content("ok"); //اعلام موفقیت آمیز بودن ثبت اطلاعات
        }

        [HttpGet]
        public ActionResult Post(int? id)
        {
            if (id == null)
                return Redirect("/");

            //todo: show the content here
            return Content("Post " + id.Value);
        }
    }
}

using System;
using System.Web;

namespace jQueryMvcSample03.Security
{
    public static class CookieHelper
    {
        public static bool CanUserVoteBasedOnCookies(this HttpContextBase httpContext, int postId, string sectionType)
        {
            string key = sectionType + "-" + postId;
            var value = httpContext.GetCookieValue(key);
            if (string.IsNullOrWhiteSpace(value))
            {
                httpContext.AddCookie(key, key);
                return true;
            }
            return false;
        }

        public static void AddCookie(this HttpContextBase httpContextBase, string cookieName, string value)
        {
            httpContextBase.AddCookie(cookieName, value, DateTime.Now.AddDays(30));
        }

        public static void AddCookie(this HttpContextBase httpContextBase, string cookieName, string value, DateTime expires)
        {
            var cookie = new HttpCookie(cookieName)
            {
                Expires = expires,
                Value = httpContextBase.Server.UrlEncode(value) // For Cookies and Unicode characters
            };
            httpContextBase.Response.Cookies.Add(cookie);
        }

        public static string GetCookieValue(this HttpContextBase httpContext, string cookieName)
        {
            var cookie = httpContext.Request.Cookies[cookieName];
            if (cookie == null)
                return string.Empty; //cookie doesn't exist

            // For Cookies and Unicode characters
            return httpContext.Server.UrlDecode(cookie.Value);
        }
    }
}

using jQueryMvcSample03.Models;

namespace jQueryMvcSample03.DataSource
{
    public interface IBlogPostsService
    {
        void SaveRating(int postId, double rating);
    }

    public class SampleService : IBlogPostsService
    {
        /// <summary>
        /// یک نمونه از متد ذخیره سازی اطلاعات پیشنهادی
        /// فقط برای ایده گرفتن
        /// بدیهی است محل قرارگیری اصلی آن در لایه سرویس برنامه شما خواهد بود
        /// </summary>
        public void SaveRating(int postId, double rating)
        {
            BlogPost post = null;
            //post = _blogCtx.Find(postId); // بر اساس شماره مطلب، مطلب یافت شده و فیلدهای آن تنظیم می‌شوند
            if (post == null) return;

            if (!post.Rating.TotalRaters.HasValue) post.Rating.TotalRaters = 0;
            if (!post.Rating.TotalRating.HasValue) post.Rating.TotalRating = 0;
            if (!post.Rating.AverageRating.HasValue) post.Rating.AverageRating = 0;

            post.Rating.TotalRaters++;
            post.Rating.TotalRating += rating;
            post.Rating.AverageRating = post.Rating.TotalRating / post.Rating.TotalRaters;

            // todo: call save changes at the end.
        }
    }
}

@using System.Text.RegularExpressions
@model IList<jQueryMvcSample03.Models.BlogPost>
<ul>
    @foreach (var item in Model)
    {
        <li>
            <fieldset>
            <legend>مطلب @item.Id</legend>
                <h5>
                    @Html.ActionLink(linkText: item.Title,
                                 actionName: "Post",
                                 controllerName: "Home",
                                 routeValues: new { id = item.Id },
                                 htmlAttributes: null)
                </h5>
                @item.Body
                <div class="post_rating">
                    @Html.Raw(Regex.Replace(@StarRatingHelper.AddStarRating(item.Id, item.Rating.AverageRating, item.Rating.TotalRaters, "BlogPost").ToHtmlString(), @">\s+<", "><"))
                </div>
            </fieldset>
        </li>
    }
</ul>

@model IList<jQueryMvcSample03.Models.BlogPost>
@{
    ViewBag.Title = "Index";
    var postInfoUrl = Url.Action(actionName: "SaveRatings", controllerName: "Home");
}
<h2>
    سیستم امتیاز دهی</h2>
@{ Html.RenderPartial("_ItemsList", Model); }
@section JavaScript
{
    <script type="text/javascript">
        $(document).ready(function () {
            $(".rating.stars.active").StarRating({
                ratingStarsSpan: '.rating.stars',
                postInfoUrl: '@postInfoUrl',
                loginUrl: '/login',
                errorHandler: function () {
                    alert('خطایی رخ داده است');
                },
                completeHandler: function () {
                    alert('با تشکر! رای شما با موفقیت ثبت شد');
                },
                onlyOneTimeHandler: function () {
                    alert('فقط یکبار می‌توانید به ازای هر مطلب رای دهید');
                }
            });
        });
    </script>
}

 public class PreciousMetal
    {
        public string Name { get; set; }
        public float Price { get; set; }
        public DateTime UpdateTime { get; set; }
    }

<pricelist currency="usd">
  <price timestamp="1349347920" per="ozt" commodity="gold">1788.70</price>
  <price timestamp="1349347860" per="ozt" commodity="palladium">665.50</price>
  <price timestamp="1349347920" per="ozt" commodity="platinum">1701.25</price>
  <price timestamp="1349347920" per="ozt" commodity="silver">34.91</price>
</pricelist>

Mapper.CreateMap<XElement, PreciousMetal>().ForMember(des => des.Price,
                                                                  op =>
                                                                  op.MapFrom(src => src.Value));

public class UnixTimestampResolver : ValueResolver<XElement, DateTime>
    {
        protected override DateTime ResolveCore(XElement source)
        {
            var origin = new DateTime(1970, 1, 1, 0, 0, 0, 0);
            return origin.AddSeconds(Convert.ToDouble(source.Attribute("timestamp").Value));
        }
    }

public class EnglishPMetalToFarsiResolver : ValueResolver<XElement, string>
    {
        readonly Dictionary<string, string> _pMetaldic = new Dictionary<string, string>
                                                       {
                                                           {"gold", "طلا"},
                                                           {"palladium", "پالادیوم"},
                                                           {"platinum", "پلاتین "},
                                                           {"silver", "نقره"}
                                                       };
        protected override string ResolveCore(XElement source)
        {
            string pMetalFarsi;
            return _pMetaldic.TryGetValue(source.Attribute("commodity").Value, out pMetalFarsi) ? pMetalFarsi : string.Empty;
        }
    }

static void Main(string[] args)
        {
            //تعریف نگاشت‌ها Mapper.CreateMap<XElement, PreciousMetal>().ForMember(des => des.Name,
                                                                  op => op.ResolveUsing<EnglishPMetalToFarsiResolver>())
                .ForMember(des => des.Price,
                           op =>
                           op.MapFrom(src => src.Value))

                .ForMember(des => des.UpdateTime, op => op.ResolveUsing<UnixTimestampResolver>());

            Mapper.AssertConfigurationIsValid();

            //دریافت قیمت‌ها از منبع داده
            var doc = XDocument.Load("http://www.xmlcharts.com/cache/precious-metals.xml");
            var priceData = doc.Descendants("pricelist").Take(1).Elements("price");

            //فراخوانی نگاشت
            var preciousMetals = Mapper.Map<IEnumerable<XElement>, IList<PreciousMetal>>(priceData);


            foreach (var preciousMetal in preciousMetals)
            {
                Console.WriteLine(preciousMetal.Name + " " + preciousMetal.Price + " " + preciousMetal.UpdateTime.ToShortDateString());
            }

            Console.ReadLine();

        }

 string data = null;
var result = data ?? "value";

if (data == null)
{
    data = "value";
}
var result = data;

class Response
{
    public string Result { set; get; }
    public int Code { set; get; }
}

 
class WebRequest
{
    public Response GetDataFromWeb(string url)
    {
        // ...
        return new Response { Result = null };
    }
}

 var webData = new WebRequest().GetDataFromWeb("https://www.dntips.ir/");
if (webData != null && webData.Result != null)
{
    Console.WriteLine(webData.Result);
}

 if (webData?.Result != null)
{
    Console.WriteLine(webData.Result);
}

 if (x != null)
{
   x.Dispose();
}

 x?.Dispose();

 var copy = OnMyEvent;
if (copy != null)
{
   copy(this, new EventArgs());
}

 OnMyEvent?.Invoke(this, new EventArgs());

 var code = webData?.Code;

 if (webData?.Code > 0)
{

}

 int count = response?.Results?.Count ?? 0;

 int? x = 10;
//var value = x?.Value; // invalid
Console.WriteLine(x?.ToString());

 if (response != null && response.Results != null && response.Results.Addresses != null
  && response.Results.Addresses[0] != null && response.Results.Addresses[0].Zip == "63368")
{

}

 if(response?.Results?.Addresses?[0]?.Zip == "63368")
{

}

 public void DoSomething(Customer customer)
{
    string address = customer?.Employees
                  ?.SingleOrDefault(x => x.IsAdmin)?.Address?.ToString();
    SendPackage(address);
}

 public void DoSomething(Customer customer)
{
   Contract.Requires(customer != null); 
   string address = customer.GetAdminAddress();
   SendPackage(address);
}