public static void PrintNumbers()
{
    var numbers = new[] { 1,2,3,5,7,90 }; // from a data source
    foreach(var item in numbers)
    {
        Console.WriteLine(item);
    }    
}

public static void PrintNumbers(Func<int,string> formula)
{
    var numbers = new[] { 1,2,3,5,7,90 };  // from a data source
    foreach(var item in numbers)
    {
        var data = formula(item);
        Console.WriteLine(data);
    }    
}

 PrintNumbers(number => string.Format("{0:n0}",number));

 PrintNumbers((number) =>{ return string.Format("{0:n0}",number); });

using System;
using System.Web;
using System.Web.Caching;
using System.Collections.Generic;

namespace WebToolkit
{
    public static class CacheManager
    {
        public static void CacheInsert(this HttpContextBase httpContext, string key, object data, int durationMinutes)
        {
            if (data == null) return;
            httpContext.Cache.Add(
                key,
                data,
                null,
                DateTime.Now.AddMinutes(durationMinutes),
                TimeSpan.Zero,
                CacheItemPriority.AboveNormal,
                null);
        }
    }
}

var item = httpContext.Cache[key];
if (item == null)
{
    item = ReadDataFromDataSource();
    if (item == null)
          return null;

    CacheInsert(httpContext, key, item, durationMinutes);
}

using System;
using System.Web;
using System.Web.Caching;
using System.Collections.Generic;

namespace WebToolkit
{
    public static class CacheManager
    {
        public static void CacheInsert(this HttpContextBase httpContext, string key, object data, int durationMinutes)
        {
            if (data == null) return;
            httpContext.Cache.Add(
                key,
                data,
                null,
                DateTime.Now.AddMinutes(durationMinutes),
                TimeSpan.Zero,
                CacheItemPriority.AboveNormal,
                null);
        }

        public static T CacheRead<T>(this HttpContextBase httpContext, string key, int durationMinutes, Func<T> ifNullRetrievalMethod)
        {
            var item = httpContext.Cache[key];
            if (item == null)
            {
                item = ifNullRetrievalMethod();
                if (item == null)
                    return default(T);

                CacheInsert(httpContext, key, item, durationMinutes);
            }
            return (T)item;
        }
    }
}

var user = HttpContext.CacheRead(
                            "Key1",
                            15,
                            () => _usersService.FindUser(userId));

   [DataContract]
    public class Book 
    {
        [DataMember]
        public int Code { get; set; }

        [DataMember]
        public string Name { get; set; }             
    }

  [ServiceContract]
    public interface ISampleService
    {
        [OperationContract]
        IEnumerable<Book> GetAll();

        [OperationContract]
        void Save( Book book );
    }

public class SampleService : ISampleService
    {
        public List<Book> ListOfBook 
        {
            get; 
            private set; 
        }

        public SampleService()
        {
            ListOfBook = new List<Book>();
        }
        public IEnumerable<Book> GetAll()
        {
            ListOfBook.AddRange( new Book[] 
            {
                new Book(){Code=1 , Name="Book1"},
                new Book(){Code=2 , Name="Book2"},
            } );
            return ListOfBook;
        }

        public void Save( Book book )
        {
            ListOfBook.Add( book );
        }
    }

 [DataContract]
    public class Book 
    {
        [DataMember]
        public int Code { get; set; }
        [DataMember]
        public string Name { get; set; }

        [DataMember]
        public string Author { get; set; }
    }

[DataMember( IsRequired = true )]
public string Author { get; set; }

  [DataContract]
    public class Book
    {
        [DataMember]
        public int Code { get; set; }
        [DataMember]
        public string Name { get; set; }

        [DataMember( IsRequired = true )]
        public string Author { get; set; }

        [OnDeserializing]
        private void OnDeserializing( StreamingContext context )
        {
            if ( string.IsNullOrEmpty( Author ) )
            {
                Author = "Masoud Pakdel";
            }
        }
    }

[DataContract]
    public class Book : IExtensibleDataObject
    {
        [DataMember]
        public int Code { get; set; }
        [DataMember]
        public string Name { get; set; }

        [DataMember]
        public string Author { get; set; }
    
        public virtual ExtensionDataObject ExtensionData
        {
            get { return _extensionData; }
            set
            {
                _extensionData = value;
            }
        }
        private ExtensionDataObject _extensionData;
    }

public IEnumerable<Book> GetAll()
        {
            ListOfBook.AddRange( new Book[] 
            {
                new Book(){Code=1 , Name="Book1", Author="Masoud Pakdel"},
                new Book(){Code=2 , Name="Book2" },
            } );
            return ListOfBook;
        }

 [ServiceBehavior( IgnoreExtensionDataObject = true )]
  public class SampleService : ISampleService

1. اگر فایل   FileX.min.js  و همچنینن فایل  FileX.js موجود باشد  .min را انتخاب می‌کند
2. برای دیباگ کردن فایل اصلی را انتخاب میکند.( FileX.js )
3. از فایلهای  -vsdoc صرف نظر میکند.چون فقط جهت استفاده از  IntelliSense هستند.

public enum PersonType
{
    Real =0,
    Legal=1
}

public class Person
{
    public long PersonId { get; set; }
    public string Name { get; set; }
    public string Family { get; set; }
    public PersonType PersonType { get; set; }

    public Person(long personId, string name, string family, PersonType personType)
    {
        PersonId = personId;
        Name = name;
        Family = family;
        PersonType = personType;
    }
}

public class PersonDto
{
    public long PersonId { get; set; }
    public string Name { get; set; }
    public string Family { get; set; }
    public PersonType PersonType { get; set; }

    public PersonDto(long personId, string name, string family, PersonType personType)
    {
        PersonId = personId;
        Name = name;
        Family = family;
        PersonType = personType;
    }
}

public class PersonList
{
    readonly List<Person> _list = new List<Person>();
    public ReadOnlyCollection<Person> GetPersons()
    {
        if (!_list.Any())
        {
            for (int i = 0; i < 100*1000; i++)
            {
                _list.Add(new Person(i + 1, "Person Name" + i, "Person Family" + i, (PersonType)(i % 2)));
            }

        }
        return _list.AsReadOnly();
    }
}

for (int i = 0; i < 100*1000; i++)
{
    _list.Add(new Person(i + 1, "Person Name" + i, "Person Family" + i, (PersonType)(i % 2)));
}

<package id="AutoMapper" version="5.1.1" targetFramework="net452" />

[TestMethod]
public void FillPersonDtoList_AutoMapperShouldMapPersonListToPersonDtoList_WhenLargeAmountOfPerson()
{
    // arrange
    var personDtoList = new List<PersonDto>(); persons = new PersonList().GetPersons();

    // act
    personDtoList = Mapper.Map<List<PersonDto>>(persons);

    //assert
    Assert.AreEqual(persons.Count, personDtoList.Count);
}
[TestMethod]
public void FillPersonDtoList_UsingHandlyAssignment_WhenLargeAmountOfPerson()
{
    // arrange
    var personDtoList = new List<PersonDto>(); persons = new PersonList().GetPersons();

    // act
    foreach (var person in persons)
    {
        personDtoList.Add(new PersonDto(person.PersonId, person.Name, person.Family, person.PersonType));
    }

    //assert
    Assert.AreEqual(persons.Count, personDtoList.Count);
}

[HtmlTargetElement("img-gravatar")]
    public class GravatarTagHelper : TagHelper
    {
        [HtmlAttributeName("email")]
        public string Email { get; set; }

        [HtmlAttributeName("alt")]
        public string Alt { get; set; }

        [HtmlAttributeName("class")]
        public string Class { get; set; }

        [HtmlAttributeName("size")]
        public int Size { get; set; }

        public override void Process(TagHelperContext context, TagHelperOutput output)
        {
            if (!string.IsNullOrWhiteSpace(Email))
            {
                var hash = Md5HashHelper.GetHash(Email);

                output.TagName = "img";
                if (!string.IsNullOrWhiteSpace(Class))
                {
                    output.Attributes.Add("class", Class); 
                }

                if (!string.IsNullOrWhiteSpace(Alt))
                {
                    output.Attributes.Add("alt", Alt);
                }
                
                output.Attributes.Add("src", GetAvatarUrl(hash, Size));
                output.TagMode = TagMode.SelfClosing;
            } 
        }

        private static string GetAvatarUrl(string hash, int size)
        {
            var sizeArg = size > 0 ? $"?s={size}" : "";

            return $"https://www.gravatar.com/avatar/{hash}{sizeArg}";
        }

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 );
        }
    }