using System.Collections.Generic;
using System.Linq;
using System.ServiceModel;
using System.Text;
using System.Threading.Tasks;

namespace MyNewsWCFLibrary
{
    [ServiceContract]
    interface IMyNewsService
    {
        [OperationContract]
        List<tblNews> GetAllNews();

        [OperationContract]
        tblNews GetNews(int tblNewsId);

        [OperationContract]
        int AddNews(tblNews News);

        [OperationContract]
        bool EditNews(tblNews News);

        [OperationContract]
        bool DeleteNews(int tblNewsId);

        [OperationContract]
        int AddCategory(tblCategory News);

        [OperationContract]
        bool DeleteCategory(int tblCategoryId);

        [OperationContract]
        List<tblCategory> GetAllCategory();
    }
}

کلاسی به نام MyNewsService با ارث‌بری از IMyNewsService ایجاد می‎شود. زیر حرف I از IMyNewsService یک خط دیده می‎‌شود که با کلیک روی آن برابر با شکل زیر عمل کنید:

ملاحظه خواهید کرد که کلیه‎ی متدها برابر با Interface ساخته خواهد شد. اکنون همانند شکل روی نشان هرم شکلی که هنگامی که روی نام کلاس کلیک می‌کنید، در سمت چپ نشان داده می‌شود کلیک کنید و گزینه Move to another file to match type name را انتخاب کنید:

به صورت خودکار محتوای این کلاس به یک فایل دیگر انتقال می‎یابد. اکنون هر کدام از متدها را به شکل دلخواه ویرایش می‎کنیم. من کد کلاس را این‎گونه تغییر دادم:

using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;

namespace MyNewsWCFLibrary
{
    class MyNewsService : IMyNewsService
    {
        private dbMyNewsEntities dbMyNews = new dbMyNewsEntities();
        public List<tblNews> GetAllNews()
        {
            return dbMyNews.tblNews.Where(p => p.IsDeleted == false).ToList();
        }

        public tblNews GetNews(int tblNewsId)
        {
            return dbMyNews.tblNews.FirstOrDefault(p => p.tblNewsId == tblNewsId);
        }

        public int AddNews(tblNews News)
        {
            dbMyNews.tblNews.Add(News);
            dbMyNews.SaveChanges();
            return News.tblNewsId;
        }

        public bool EditNews(tblNews News)
        {
            try
            {
                dbMyNews.Entry(News).State = EntityState.Modified;
                dbMyNews.SaveChanges();
                return true;
            }
            catch (Exception exp)
            {
                return false;
            }
        }

        public bool DeleteNews(int tblNewsId)
        {
            try
            {
                tblNews News = dbMyNews.tblNews.FirstOrDefault(p => p.tblNewsId == tblNewsId);
                News.IsDeleted = true;
                dbMyNews.SaveChanges();
            return true;
            }
            catch (Exception exp)
            {
                return false;
            }
        }

        public int AddCategory(tblCategory Category)
        {
            dbMyNews.tblCategory.Add(Category);
            dbMyNews.SaveChanges();
            return Category.tblCategoryId;
        }

        public bool DeleteCategory(int tblCategoryId)
        {
            try
            {
                tblCategory Category = dbMyNews.tblCategory.FirstOrDefault(p => p.tblCategoryId == tblCategoryId);
                Category.IsDeleted = true;
                dbMyNews.SaveChanges();
                return true;
            }
            catch (Exception exp)
            {
                return false;
            }
        }

        public List<tblCategory> GetAllCategory()
        {
            return dbMyNews.tblCategory.Where(p => p.IsDeleted == false).ToList();
        }
    }
}

ولی شما ممکن است درباره‎ی حذف، دوست داشته باشید رکوردها از پایگاه داده حذف شوند و نه این‌که با یک فیلد بولی آن‎ها را مدیریت کنید. در این صورت کد شما می‎تواند این‎گونه نوشته شود:

using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;

namespace MyNewsWCFLibrary
{
    class MyNewsService : IMyNewsService
    {
        private dbMyNewsEntities dbMyNews = new dbMyNewsEntities();
        public List<tblNews> GetAllNews()
        {
            return dbMyNews.tblNews.ToList();
        }

        public tblNews GetNews(int tblNewsId)
        {
            return dbMyNews.tblNews.FirstOrDefault(p => p.tblNewsId == tblNewsId);
        }

        public int AddNews(tblNews News)
        {
            dbMyNews.tblNews.Add(News);
            dbMyNews.SaveChanges();
            return News.tblNewsId;
        }

        public bool EditNews(tblNews News)
        {
            try
            {
                dbMyNews.Entry(News).State = EntityState.Modified;
                dbMyNews.SaveChanges();
                return true;
            }
            catch (Exception exp)
            {
                return false;
            }
        }

        public bool DeleteNews(tblNews News)
        {
            try
            {
                dbMyNews.tblNews.Remove(News);
                dbMyNews.SaveChanges();
            return true;
            }
            catch (Exception exp)
            {
                return false;
            }
        }

        public int AddCategory(tblCategory Category)
        {
            dbMyNews.tblCategory.Add(Category);
            dbMyNews.SaveChanges();
            return Category.tblCategoryId;
        }

        public bool DeleteCategory(tblCategory Category)
        {
            try
            {
                dbMyNews.tblCategory.Remove(Category);
                dbMyNews.SaveChanges();
                return true;
            }
            catch (Exception exp)
            {
                return false;
            }
        }

        public List<tblCategory> GetAllCategory()
        {
            return dbMyNews.tblCategory.ToList();
        }
    }
}

البته باید در نظر داشته باشید که در صورت هر گونه تغییر در پارامترهای ورودی، لایه‌ی Interface نیز باید تغییر کند. گونه‌ی دیگر نوشتن متد حذف خبر می‌تواند به صورت زیر باشد:

public bool DeleteNews(int tblNewsId)
        {
            try
            {
                tblNews News = dbMyNews.tblNews.FirstOrDefault(p => p.tblNewsId == tblNewsId);
                dbMyNews.tblNews.Remove(News); 
                dbMyNews.SaveChanges();
            return true;
            }
            catch (Exception exp)
            {
                return false;
            }
        }

در بخش 5 درباره‌ی تغییرات App.Config خواهم نوشت.

Unable to update database to match the current model because there are pending changes and 
automatic migration is disabled. Either write the pending model changes to a code-based migration 
or enable automatic migration. Set DbMigrationsConfiguration.AutomaticMigrationsEnabled to true
to enable automatic migration.

Add-Migration AddSomeProp2ToProject

namespace EF_Sample02.Migrations
{
    using System.Data.Entity.Migrations;
    
    public partial class AddSomeProp2ToProject : DbMigration
    {
        public override void Up()
        {
            AddColumn("Projects", "SomeProp", c => c.String());
            AddColumn("Projects", "SomeProp2", c => c.String());
        }
        
        public override void Down()
        {
            DropColumn("Projects", "SomeProp2");
            DropColumn("Projects", "SomeProp");
        }
    }
}

Update-Database -Verbose

Using NuGet project 'EF_Sample02'.
Using StartUp project 'EF_Sample02'.
Target database is: 'testdb2012' (DataSource: (local), Provider: System.Data.SqlClient, Origin: Configuration).
Applying explicit migrations: [201205061835024_AddSomeProp2ToProject].
Applying explicit migration: 201205061835024_AddSomeProp2ToProject.
ALTER TABLE [Projects] ADD [SomeProp] [nvarchar](max)
ALTER TABLE [Projects] ADD [SomeProp2] [nvarchar](max)
[Inserting migration history record]

Add-Migration AddSomeProp3ToProject
Update-Database -Verbose

get-help update-database -detailed

Update-Database -TargetMigration:"AddSomeProp2ToProject" -Verbose

Using NuGet project 'EF_Sample02'.
Using StartUp project 'EF_Sample02'.
Target database is: 'testdb2012' (DataSource: (local), Provider: System.Data.SqlClient, Origin: Configuration).
Reverting migrations: [201205061845485_AddSomeProp3ToProject].
Reverting explicit migration: 201205061845485_AddSomeProp3ToProject.
DECLARE @var0 nvarchar(128)
SELECT @var0 = name
FROM sys.default_constraints
WHERE parent_object_id = object_id(N'Projects')
AND col_name(parent_object_id, parent_column_id) = 'SomeProp3';
IF @var0 IS NOT NULL
    EXECUTE('ALTER TABLE [Projects] DROP CONSTRAINT ' + @var0)
ALTER TABLE [Projects] DROP COLUMN [SomeProp3]
[Deleting migration history record]

namespace EF_Sample02.Migrations
{
    using System.Data.Entity.Migrations;
    
    public partial class AddSomeProp3ToProject : DbMigration
    {
        public override void Up()
        {
            AddColumn("Projects", "SomeProp3", c => c.String(defaultValue: "some data"));
            Sql("Update Projects set SomeProp3=N'some data'");
        }
        
        public override void Down()
        {
            DropColumn("Projects", "SomeProp3");
        }
    }
}

public ColumnModel String(bool? nullable = null, int? maxLength = null, bool? fixedLength = null, 
bool? isMaxLength = null, bool? unicode = null, string defaultValue = null, string defaultValueSql = null, 
string name = null, string storeType = null)

ALTER TABLE [Projects] ADD [SomeProp3] [nvarchar](max) DEFAULT 'some data'

namespace EF_Sample02.Migrations
{
    using System;
    using System.Data.Entity.Migrations;

    internal sealed class Configuration : DbMigrationsConfiguration<EF_Sample02.Sample2Context>
    {
        public Configuration()
        {
            this.AutomaticMigrationsEnabled = false;
            this.AutomaticMigrationDataLossAllowed = true;
        }

        protected override void Seed(EF_Sample02.Sample2Context context)
        {
            context.Users.AddOrUpdate(
                 a => a.Name,
                 new Models.User { Name = "Vahid", AddDate = DateTime.Now },
                 new Models.User { Name = "Test", AddDate = DateTime.Now });
        }
    }
}

Update-Database -Verbose -Script

ALTER TABLE [Projects] ADD [SomeProp5] [nvarchar](max)
INSERT INTO [__MigrationHistory] ([MigrationId], [CreatedOn], [Model], [ProductVersion]) VALUES 
('201205060852004_AutomaticMigration', '2012-05-06T08:52:00.937Z', 0x1F8B0800000............ '4.3.1')

Update-Database -Verbose -Script -SourceMigration:"stepName"

Add-Migration AddSomePropToProject
Update-Database -Verbose -Script

    public static class EnumHelpers
    {
        public static IEnumerable<SelectListItem> GetItems(
            this Type enumType, int? selectedValue)
        {
            if (!typeof(Enum).IsAssignableFrom(enumType))
            {
                throw new ArgumentException("Type must be an enum");
            }

            var names = Enum.GetNames(enumType);
            var values = Enum.GetValues(enumType).Cast<int>();

            var items = names.Zip(values, (name, value) =>
                    new SelectListItem
                    {
                        Text = GetName(enumType, name),
                        Value = value.ToString(),
                        Selected = value == selectedValue
                    }
                );
            return items;
        }

        static string GetName(Type enumType, string name)
        {
            var result = name;

            var attribute = enumType
                .GetField(name)
                .GetCustomAttributes(inherit: false)
                .OfType<DisplayAttribute>()
                .FirstOrDefault();

            if (attribute != null)
            {
                result = attribute.GetName();
            }

            return result;
        }
    }

public class SubCategory : BaseEntity
{
        public string Title { get; set; }
        [ForeignKey("CategoryId")]
        public virtual Category Category { get; set; }
        public Guid CategoryId { get; set; }
}

public class SubCategoryConfiguration : EntityTypeConfiguration<SubCategory>
 {
        public SubCategoryConfiguration()
        {
            Property(p => p.CategoryId).HasColumnAnnotation("Index", new IndexAnnotation(new IndexAttribute("AK_SubCategory", 1){ IsUnique = true}));
            Property(p => p.Title).HasMaxLength(30).IsRequired().HasColumnAnnotation("Index", new IndexAnnotation(new IndexAttribute("AK_SubCategory", 2){ IsUnique = true}));
            Property(so => so.RowVersion).IsRowVersion();
        }
}

namespace ShowAlertSignalR.Models
{
    public class Product
    {
        public int Id { get; set; }
        public string Title { get; set; }
        public string Description { get; set; }
        public float Price { get; set; }
        public Category Category { get; set; }

    }

    public enum Category
    {
        [Display(Name = "دسته بندی اول")]
        Cat1,
        [Display(Name = "دسته بندی دوم")]
        Cat2,
        [Display(Name = "دسته بندی سوم")]
        Cat3
    }
}

namespace ShowAlertSignalR.Models
{
    public class ProductDbContext : DbContext
    {
        public ProductDbContext() : base("productSample")
        {
            Database.Log = sql => Debug.Write(sql);
        }
        public DbSet<Product> Products { get; set; }
    }
}

[HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create(Product product)
        {
            if (ModelState.IsValid)
            {
                db.Products.Add(product);
                db.SaveChanges();
                return RedirectToAction("Index");
            }

            return View(product);
        }

public ActionResult Index(bool notifyUsers = false)
        {
            ViewBag.NotifyUsers = notifyUsers;
            return View(db.Products.ToList());
        }

[HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create(Product product)
        {
            if (ModelState.IsValid)
            {
                db.Products.Add(product);
                db.SaveChanges();
                return RedirectToAction("Index", new { notifyUsers = true });
            }

            return View(product);
        }

namespace ShowAlertSignalR.Hubs
{
    public class NotificationHub : Hub
    {
        public void SendNotification()
        {
            Clients.Others.ShowNotification();
        }
    }
}

@section scripts
{
    
    <script src="~/Scripts/jquery.signalR-2.0.2.min.js"></script>
    <script src="~/signalr/hubs"></script>
    <script>

        var notify = $.connection.notificationHub;
        notify.client.showNotification = function() {
            $('#result').append("<div class='alert alert-info alert-dismissable'>" +
                "<button type='button' class='close' data-dismiss='alert' aria-hidden='true'>&times;</button>" +
            "رکورد جدیدی هم اکنون ثبت گردید، برای مشاهده آن صفحه را بروزرسانی کنید" + "</div>");
        };
        $.connection.hub.start().done(function() {
            @{
                if (ViewBag.NotifyUsers)
                {
                    <text>notify.server.sendNotification();</text>
                }
            }
        });
    </script>
}

using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

namespace iTextSharpTests
{
   class Program
   {
       static void Main(string[] args)
       {
           using (var pdfDoc = new Document(PageSize.A4))
           {
               PdfWriter.GetInstance(pdfDoc, new FileStream("Test.pdf", FileMode.Create));
               pdfDoc.Open();

               var chunk = new Chunk("آزمایش");
               pdfDoc.Add(chunk);
           }
       }
   }
}

using System;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

namespace iTextSharpTests
{
   class Program
   {
       static void Main(string[] args)
       {
           using (var pdfDoc = new Document(PageSize.A4))
           {
               PdfWriter.GetInstance(pdfDoc, new FileStream("Test.pdf", FileMode.Create));
               pdfDoc.Open();

               var fontPath = Environment.GetEnvironmentVariable("SystemRoot") + "\\fonts\\tahoma.ttf";
               var baseFont = BaseFont.CreateFont(fontPath, BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
               var tahomaFont = new Font(baseFont, 10, Font.NORMAL, BaseColor.BLACK);

               var chunk = new Chunk("آزمایش",tahomaFont);
               pdfDoc.Add(chunk);
           }
       }
   }
}

using System;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

namespace iTextSharpTests
{
   class Program
   {
       static void Main(string[] args)
       {
           using (var pdfDoc = new Document(PageSize.A4))
           {
               var pdfWriter = PdfWriter.GetInstance(pdfDoc, new FileStream("Test.pdf", FileMode.Create));
               pdfDoc.Open();

               var fontPath = Environment.GetEnvironmentVariable("SystemRoot") + "\\fonts\\tahoma.ttf";
               var baseFont = BaseFont.CreateFont(fontPath, BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
               var tahomaFont = new Font(baseFont, 10, Font.NORMAL, BaseColor.BLACK);

               ColumnText ct = new ColumnText(pdfWriter.DirectContent);
               ct.RunDirection = PdfWriter.RUN_DIRECTION_RTL;
               ct.SetSimpleColumn(100, 100, 500, 800, 24, Element.ALIGN_RIGHT);

               var chunk = new Chunk("آزمایش", tahomaFont);

               ct.AddElement(chunk);
               ct.Go();
           }
       }
   }
}

using System;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

namespace iTextSharpTests
{
   class Program
   {
       static void Main(string[] args)
       {
           using (var pdfDoc = new Document(PageSize.A4))
           {
               var pdfWriter = PdfWriter.GetInstance(pdfDoc, new FileStream("Test.pdf", FileMode.Create));
               pdfDoc.Open();

               var fontPath = Environment.GetEnvironmentVariable("SystemRoot") + "\\fonts\\tahoma.ttf";
               var baseFont = BaseFont.CreateFont(fontPath, BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
               var tahomaFont = new Font(baseFont, 10, Font.NORMAL, BaseColor.BLACK);

               PdfPTable table = new PdfPTable(numColumns: 1);
               table.RunDirection = PdfWriter.RUN_DIRECTION_RTL;
               table.ExtendLastRow = true;

               PdfPCell pdfCell = new PdfPCell(new Phrase("آزمایش", tahomaFont));
               pdfCell.RunDirection = PdfWriter.RUN_DIRECTION_RTL;

               table.AddCell(pdfCell);
               pdfDoc.Add(table);
           }
       }
   }
}

using System;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

namespace iTextSharpTests
{
   public class PageEvents : PdfPageEventHelper
   {
       Font _font;
       public PageEvents()
       {
           var fontPath = Environment.GetEnvironmentVariable("SystemRoot") + "\\fonts\\tahoma.ttf";
           var baseFont = BaseFont.CreateFont(fontPath, BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
           _font = new Font(baseFont, 10, Font.NORMAL, BaseColor.BLACK);
       }

       public override void OnStartPage(PdfWriter writer, Document document)
       {
           base.OnStartPage(writer, document);

           PdfPTable table = new PdfPTable(numColumns: 1);
           table.RunDirection = PdfWriter.RUN_DIRECTION_RTL;

           PdfPCell pdfCell = new PdfPCell(new Phrase("سر صفحه در صفحه:  " + writer.PageNumber, _font));
           pdfCell.RunDirection = PdfWriter.RUN_DIRECTION_RTL;
           pdfCell.HorizontalAlignment = Element.ALIGN_CENTER;           

           table.AddCell(pdfCell);
           document.Add(table);
       }
   }

   class Program
   {
       static void Main(string[] args)
       {
           using (var pdfDoc = new Document(PageSize.A4))
           {
               var pdfWriter = PdfWriter.GetInstance(pdfDoc, new FileStream("Test.pdf", FileMode.Create));
               pdfWriter.PageEvent = new PageEvents();
               pdfDoc.Open();

               var fontPath = Environment.GetEnvironmentVariable("SystemRoot") + "\\fonts\\tahoma.ttf";
               var baseFont = BaseFont.CreateFont(fontPath, BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
               var tahomaFont = new Font(baseFont, 10, Font.NORMAL, BaseColor.BLACK);

               PdfPTable table = new PdfPTable(numColumns: 1);
               table.RunDirection = PdfWriter.RUN_DIRECTION_RTL;
               table.ExtendLastRow = true;              

               PdfPCell pdfCell = new PdfPCell(new Phrase("آزمایش", tahomaFont));
               pdfCell.RunDirection = PdfWriter.RUN_DIRECTION_RTL;                                             
              
               table.AddCell(pdfCell);
               pdfDoc.Add(table);

               pdfDoc.NewPage();
           }
       }
   }
}