protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Conventions.Add(new FunctionsConvention<MyContext>("dbo"));
    }

• نوع خروجی تابع باید از <IQueryable<T  باشد. T باید از جنسی باشد که معادل EDM آن موجود باشد. T می‌تواند از انواع اصلی (Primitive) باشد که در EF پشتیبانی می‌شوند (رجوع شود به  Entity Data Model: Primitive Data Types   )به طور مثال، int قابل استفاده است ولی uint خیر و یا می‌تواند از انواع غیر اصلی (  non-primitive ) باشند (enum/complex type/entity type ) که در مدل شما تعریف شده‌اند.
• پارامترهای متد باید از نوع اسکالر (primitive یا enum) باشند که قابل map شدن به نوع‌های EF باشند.
  
• نام متد،  DbFunction.FunctionName   و querystring ایی که به CreateQuery  پاس داده می‌شود باید همگی یکسان باشند.

1. بررسی وجود کتاب
2. بررسی تعداد موجود یک کتاب در کتابخانه
3. بررسی وضعیت امانی کتاب (آیا کتاب در دست کسی از قبل امانت است؟ یا کتاب برای امانت آزاد است؟)
4. در صورتی که کتابی بیش از زمان مورد نظر در دست کسی امانت است، با یک پیامک از او بخواهیم که کتاب را بازگرداند.

    class Book
    {
        public int Id { get; set; }
        public string Title { get; set; }
        public int Quantity { get; set; }
        public bool IsLoanable { get; set; }
    }

 class User
    {
        public int Id { get; set; }
        public string Title { get; set; }
        public  string CellPhoneNumber { get; set; }
    }

  class Loan
    {
       public DateTime ExpiredDate { get; set; }
        public User User { get; set; }
    }

 class BookManager
    {
        public Book GetBook(int id)
        {
                return new Book()
                {
                    Id=id,
                    Title = "a book",
                    Quantity = 3,
                    IsLoanable = true
                };
        }
    }

 public int IsLoan(int bookId)
        {
            return 2;
        }

        public List<Loan> GetLoans(int bookId)
        {
            return new List<Loan>()
            {
                new Loan()
                {
                    ExpiredDate = DateTime.Now.AddDays(-15),
                    User = new User()
                {
                    Id = 2,
                    Title = "User1",
                    CellPhoneNumber = "342342424"
                }
                },
                new Loan()
                {
                    ExpiredDate = DateTime.Now.AddDays(5),
                    User = new User()
                        {
                            Id = 56,
                            Title = "User56",
                            CellPhoneNumber = "324324324324"
                        }
                }
            };
        }

   class SmsManager
    {
        public void SendMessage(string number)
        {
            Console.WriteLine("please take back the book to the library : "+number);
        }
    }

    class FacadeBookLoan
    {
        private readonly BookManager _bookManager;
        private readonly LoanManager _loanManager;
        private readonly SmsManager _smsManager;
        public FacadeBookLoan()
        {
            _bookManager = new BookManager();
            _loanManager=new LoanManager();
            _smsManager=new SmsManager();
        }

        public int IsLoanable(int bookId)
        {
            var book = _bookManager.GetBook(2);
            if (book == null)
                return -2;
            if (!book.IsLoanable)
                return -1;
            var howManyBookIsLoaned = _loanManager.IsLoan(bookId);

            if(howManyBookIsLoaned>0) ManageLoaners(bookId);

            return book.Quantity - howManyBookIsLoaned;
        }

        private void ManageLoaners(int bookId)
        {
            var loans = _loanManager.GetLoans(bookId);

            foreach (var loan in loans)
            {
                if (loan.ExpiredDate > DateTime.Now)
                {
                    _smsManager.SendMessage(loan.User.CellPhoneNumber);
                }
            }
        }
    }

var myfacade=new FacadeBookLoan();
var loansCount= myfacade.IsLoanable(2);
Console.WriteLine(loansCount > 0 ? "you can loan the book" : "you can't loan the book");

please take back the book to the library : 324324324324
you can loan the book

PM> install-package AutoMapper
PM> install-package EntityFramework

public class BlogPost
{
    public int Id { get; set; }
    public string Title { get; set; }
    public string Content { get; set; }
 
    [ForeignKey("UserId")]
    public virtual User User { get; set; }
    public int UserId { get; set; }
}

public class User
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int Age { get; set; }
 
    public virtual ICollection<BlogPost> BlogPosts { get; set; }
}

public class UserViewModel
{
    public int Id { set; get; }
    public string Name { set; get; }
 
    public ICollection<BlogPost> BlogPosts { get; set; }
}

public class TestProfile : Profile
{
    protected override void Configure()
    {
        this.CreateMap<User, UserViewModel>();
    }
 
    public override string ProfileName
    {
        get { return this.GetType().Name; }
    }
}

Mapper.Initialize(cfg => // In Application_Start()
{
    cfg.AddProfile<TestProfile>();
});

using (var context = new MyContext())
{
    var user1 = context.Users.FirstOrDefault();
    if (user1 != null)
    {
        var uiUser = new UserViewModel();
        Mapper.Map(source: user1, destination: uiUser);
 
        Console.WriteLine(uiUser.Name);
        foreach (var post in uiUser.BlogPosts)
        {
            Console.WriteLine(post.Title);
        }
    }
}

 var user1 = context.Users.Include(user => user.BlogPosts).FirstOrDefault();

 var uiUser = context.Users.Project().To<UserViewModel>().FirstOrDefault();

    #region my model

    [KnownType(typeof(model1))]
    [KnownType(typeof(model2))]
    [KnownType(typeof(model3))]
    public class TaskGroupObjects : List<IBaseObject>
    {
        #region sortFields
        class compare : IComparer<IBaseObject>
        {
            public int Compare(IBaseObjectfield1, IBaseObjectfield2)
            {
                return field1.Order - field2.Order;
            }
        }

        public void sortByOrder()
        {
            Sort(new compare());
        }
        #endregion
    }

public static bool HasProperty(this object your model, string propertyName)
{
    return obj.GetType().GetProperty(propertyName) != null;
}

namespace KendoUI07.Models
{
    public class Registration
    {
        public int Id { set; get; }
        public string UserName { set; get; }
        public string CourseName { set; get; }
        public int Credit { set; get; }
        public string Email { set; get; }
        public string Tel { set; get; }
    }
}

    <script type="text/javascript">
        $(function () {
            var model = kendo.data.Model.define({
                id: "Id",
                fields: {
                    Id: { type: 'number' }, // leave this set to 0 or undefined, so Kendo knows it is new.
                    UserName: { type: 'string' },
                    CourseName: { type: 'string' },
                    Credit: { type: 'number' },
                    Email: { type: 'string' },
                    Tel: { type: 'string' }
                }
            });
        });
    </script>

    <script type="text/javascript">
        $(function () {
            var viewModel = kendo.observable({
                accepted: false,
                course: new model()
            });
        });
    </script>

    <script type="text/javascript">
        $(function () {
            var model = kendo.data.Model.define({
            // ...
            });

            var viewModel = kendo.observable({
            // ...
            });

            kendo.bind($("#coursesSection"), viewModel);
        });
    </script>

<input type="text" id="UserName" name="UserName" class="k-textbox"
       data-bind="value:course.UserName"
       required />

<input type="checkbox" name="Accept"
       data-bind="checked:accepted"
       required />

<button class="k-button"
        data-bind="enabled: accepted, click: doSave"
        type="submit">
       ارسال
</button>

    <script type="text/javascript">
        $(function () {
            var model = kendo.data.Model.define({
                //...
            });

            var dataSource = new kendo.data.DataSource({
                type: 'json',
                transport: {
                    read: {
                        url: "api/registrations",
                        dataType: "json",
                        contentType: 'application/json; charset=utf-8',
                        type: 'GET'
                    },
                    create: {
                        url: "api/registrations",
                        contentType: 'application/json; charset=utf-8',
                        type: "POST"
                    },
                    update: {
                        url: function (course) {
                            return "api/registrations/" + course.Id;
                        },
                        contentType: 'application/json; charset=utf-8',
                        type: "PUT"
                    },
                    destroy: {
                        url: function (course) {
                            return "api/registrations/" + course.Id;
                        },
                        contentType: 'application/json; charset=utf-8',
                        type: "DELETE"
                    },
                    parameterMap: function (data, type) {
                        // Convert to a JSON string.  Without this step your content will be form encoded.
                        return JSON.stringify(data);
                    }
                },
                schema: {
                    model: model
                },
                error: function (e) {
                    alert(e.errorThrown);
                },
                change: function (e) {
                    // فراخوانی در زمان دریافت اطلاعات از سرور و یا تغییرات محلی
                    viewModel.set("coursesDataSourceRows", new kendo.data.ObservableArray(this.view()));
                }
            });

            var viewModel = kendo.observable({
                //...
            });

            kendo.bind($("#coursesSection"), viewModel);
            dataSource.read(); // دریافت لیست موجود از سرور در آغاز کار
        });
    </script>

    <script type="text/javascript">
        $(function () {
            $("#coursesSection").kendoValidator({
                // ...
            });

            var model = kendo.data.Model.define({
                // ...
            });

            var dataSource = new kendo.data.DataSource({
                // ...
            });

            var viewModel = kendo.observable({
                accepted: false,
                course: new model(),
                doSave: function (e) {
                    e.preventDefault();
                    console.log("this", this.course);
                    var validator = $("#coursesSection").data("kendoValidator");
                    if (validator.validate()) {
                        if (this.course.Id == 0) {
                            dataSource.add(this.course);
                        }
                        dataSource.sync(); // push to the server
                        this.set("course", new model()); // reset controls
                    }
                },
                resetModel: function (e) {
                    e.preventDefault();
                    this.set("course", new model());
                }            
             });

            kendo.bind($("#coursesSection"), viewModel);
            dataSource.read(); // دریافت لیست موجود از سرور در آغاز کار
        });
    </script>

<button class="k-button"
        data-bind="enabled: accepted, click: doSave"
        type="submit">
       ارسال
</button>
<button class="k-button" data-bind="click: resetModel">از نو</button>

using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;
using KendoUI07.Models;

namespace KendoUI07.Controllers
{
    public class RegistrationsController : ApiController
    {
        public HttpResponseMessage Delete(int id)
        {
            var item = RegistrationsDataSource.LatestRegistrations.FirstOrDefault(x => x.Id == id);
            if (item == null)
                return Request.CreateResponse(HttpStatusCode.NotFound);

            RegistrationsDataSource.LatestRegistrations.Remove(item);
            return Request.CreateResponse(HttpStatusCode.OK, item);
        }

        public IEnumerable<Registration> Get()
        {
            return RegistrationsDataSource.LatestRegistrations;
        }

        public HttpResponseMessage Post(Registration registration)
        {
            if (!ModelState.IsValid)
                return Request.CreateResponse(HttpStatusCode.BadRequest);

            var id = 1;
            var lastItem = RegistrationsDataSource.LatestRegistrations.LastOrDefault();
            if (lastItem != null)
            {
                id = lastItem.Id + 1;
            }
            registration.Id = id;
            RegistrationsDataSource.LatestRegistrations.Add(registration);

            // ارسال آی دی مهم است تا از ارسال رکوردهای تکراری جلوگیری شود
            return Request.CreateResponse(HttpStatusCode.Created, registration);
        }

        [HttpPut] // Add it to fix this error: The requested resource does not support http method 'PUT'
        public HttpResponseMessage Update(int id, Registration registration)
        {
            var item = RegistrationsDataSource.LatestRegistrations
                                        .Select(
                                            (prod, index) =>
                                                new
                                                {
                                                    Item = prod,
                                                    Index = index
                                                })
                                        .FirstOrDefault(x => x.Item.Id == id);
            if (item == null)
                return Request.CreateResponse(HttpStatusCode.NotFound);


            if (!ModelState.IsValid || id != registration.Id)
                return Request.CreateResponse(HttpStatusCode.BadRequest);

            RegistrationsDataSource.LatestRegistrations[item.Index] = registration;
            return Request.CreateResponse(HttpStatusCode.OK);
        }
    }
}

    <script type="text/javascript">
        $(function () {
            // ...
            var viewModel = kendo.observable({
                accepted: false,
                course: new model(),
                coursesDataSourceRows: new kendo.data.ObservableArray([]),
                doSave: function (e) {
                       // ...
                },
                resetModel: function (e) {
                      // ...
                },
                totalPrice: function () {
                    var sum = 0;
                    $.each(this.get("coursesDataSourceRows"), function (index, item) {
                        sum += item.Credit;
                    });
                    return sum;
                },
                deleteCourse: function (e) {
                    // the current data item is passed as the "data" field of the event argument
                    var course = e.data;
                    dataSource.remove(course);
                    dataSource.sync(); // push to the server
                },
                editCourse: function(e) {
                    // the current data item is passed as the "data" field of the event argument
                    var course = e.data;
                    this.set("course", course);
                }
            });

            kendo.bind($("#coursesSection"), viewModel);
            dataSource.read(); // دریافت لیست موجود از سرور در آغاز کار
        });
    </script>

    <script type="text/javascript">
        $(function () {
            var dataSource = new kendo.data.DataSource({
                //...
                change: function (e) {
                    // فراخوانی در زمان دریافت اطلاعات از سرور و یا تغییرات محلی
                    viewModel.set("coursesDataSourceRows", new kendo.data.ObservableArray(this.view()));
                }
            });
        });
    </script>

public class User
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string UserName { get; set; }


    public static List<User> GetUsers()
    {
        return new List<User>()
        {
            new()
            {
                Id = 1,
                FirstName = "علی",
                LastName = "یگانه مقدم",
                UserName = "yeganehaym"
            },
            new ()
            {
                Id = 2,
                FirstName = "وحید",
                LastName = "نصیری",
                UserName = "VahidN"
            },
        };
    }
}

[ApiController]
[Route("/api/[controller]/{id?}")]
public class UserController : ControllerBase
{

    [HttpGet]
    public User GetUser(int id)
    {
        var users = Users.User.GetUsers();
        var user = users.FirstOrDefault(x => x.Id == id);
        return user;
    }
}

public class Product
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int Price { get; set; }
    public  int Quantity { get; set; }


    public static List<Product> GetProducts()
    {
        return new List<Product>()
        {
            new()
            {
                Id = 1,
                Name = "LCD",
                Price = 20000,
                Quantity = 10
            },
            new()
            {
                Id = 1,
                Name = "Mouse",
                Price = 320000,
                Quantity = 15
            },
            new()
            {
                Id = 1,
                Name = "Keyboard",
                Price = 50000,
                Quantity = 25
            },
        };
    }
}

[ApiController]
[Route("api/[controller]")]
public class ProductController : ControllerBase
{

    [HttpGet]
    public List<Product> GetProducts()
    {
        return Product.GetProducts();
    }

}

{
    "Routes":[
        
        {
        "DownstreamPathTemplate":"/api/User/{id}",
        "DownstreamScheme":"https",
        "DownstreamHostAndPorts":[
            {
                "Host":"localhost",
                "Port":"7279"
            }
        ],
        "UpstreamPathTemplate":"/GetUser/{id}",
        "UpstreamHttpMethod":[
            "GET"
        ]},
        {
        "DownstreamPathTemplate":"/api/Product",
        "DownstreamScheme":"https",
        "DownstreamHostAndPorts":[
            {
                "Host":"localhost",
                "Port":"7261"
            }
        ],
     
        "UpstreamPathTemplate":"/Products",
        "UpstreamHttpMethod":[
            "GET"
        ]
        }
    ]
    
   
}

builder.Services.AddOcelot();

app.UseOcelot();

builder.Configuration.SetBasePath(builder.Environment.ContentRootPath)    
    .AddJsonFile("ocelot.json", optional: false, reloadOnChange: true);

builder.Configuration.SetBasePath(builder.Environment.ContentRootPath)    
    .AddJsonFile("ocelot.json", optional: false, reloadOnChange: true)
    .AddJsonFile($"ocelot.{builder.Environment.EnvironmentName}.json", optional: false, reloadOnChange: true);

Install-Package Ocelot.Cache.CacheManager

builder.Services.AddOcelot()
    .AddCacheManager(x => x.WithDictionaryHandle());

"FileCacheOptions":{
      "TtlSeconds":30,
       "Region":"custom"
}

{
    "Routes":[
        
        {
        "DownstreamPathTemplate":"/api/User/{id}",
        "DownstreamScheme":"https",
        "DownstreamHostAndPorts":[
            {
                "Host":"localhost",
                "Port":"7279"
            }
        ],
        "UpstreamPathTemplate":"/GetUser/{id}",
        "UpstreamHttpMethod":[
            "GET"
        ]
        },
        {
        "DownstreamPathTemplate":"/api/Product",
        "DownstreamScheme":"https",
        "DownstreamHostAndPorts":[
            {
                "Host":"localhost",
                "Port":"7261"
            }
        ],
     
        "UpstreamPathTemplate":"/Products",
        "UpstreamHttpMethod":[
            "GET"
        ],
            "FileCacheOptions":{
                "TtlSeconds":30,
                "Region":"custom"
            }
        }
    ]
    
   
}

       "RateLimitOptions":{
                "ClientWhitelist":[
                ],
                "EnableRateLimiting":true,
                "Period":"5s",
                "PeriodTimespan":1,
                "Limit":1,
                "HttpStatusCode":429
            }

{
    "Routes":[
        
        {
        "DownstreamPathTemplate":"/api/User/{id}",
        "DownstreamScheme":"https",
        "DownstreamHostAndPorts":[
            {
                "Host":"localhost",
                "Port":"7279"
            }
        ],
        "UpstreamPathTemplate":"/GetUser/{id}",
        "UpstreamHttpMethod":[
            "GET"
        ],
        "FileCacheOptions":{
            "TtlSeconds":30,
            "Region":"custom"
        }
        },
        {
        "DownstreamPathTemplate":"/api/Product",
        "DownstreamScheme":"https",
        "DownstreamHostAndPorts":[
            {
                "Host":"localhost",
                "Port":"7261"
            }
        ],
     
        "UpstreamPathTemplate":"/Products",
        "UpstreamHttpMethod":[
            "GET"
        ],
            "RateLimitOptions":{
                "ClientWhitelist":[
                ],
                "EnableRateLimiting":true,
                "Period":"5s",
                "PeriodTimespan":1,
                "Limit":1,
                "HttpStatusCode":429
            }
        }
    ],
    "DangerousAcceptAnyServerCertificateValidator": true
    
   
}

Action<object, EventArgs> handler1 = (object obj, EventArgs args) => ShowDialog();

Action<object, EventArgs> handler2 = (object _, EventArgs _) => ShowDialog();
// OR
Action<object, EventArgs> handler3 = (_, _) => ShowDialog();

button1.Click += (s, e) => ShowDialog();

 button1.Click += (_, _) => ShowDialog();

namespace CS9Features
{
    public class LambdasTests
    {
        public void Test()
        {
            string text = "{0} is a good user !";
            PrintItems(item => string.Format(text, item));
        }

        private void PrintItems(Func<string, string> formatFunc)
        {
            foreach (var item in new[] { "User 1", "User 2" })
            {
                Console.WriteLine(formatFunc(item));
            }
        }
    }
}

const string text = "{0} is a good user !";
PrintItems(static item => string.Format(text, item));

using System;

namespace AOP00
{
    class Program
    {
        static void Main(string[] args)
        {
            Log.Debug("Program has started.");
            //.....
            try
            {

            }
            catch (Exception ex)
            {
                Log.Error(ex);
                throw;
            }
            finally
            {
                //.....
                Log.Debug("Program has ended.");
            }
        }
    }
}

        public User GetUserById(int id)
        {
            if (Cache.ExistsFor(id))
            {
                return Cache[id];
            }
            else
            {
                var user = LoadFromDb(id);
                Cache.AddFor("User", id, user);
                return user;
            }
        }

@{
    ViewBag.Title = "Index";

    var categoryService = ObjectFactory.Container.GetInstance<ICategoryService>();
    var list = categoryService.GetAllCategories();
}

public class DuplicateInfo : ActionFilterAttribute
    {
        public override void OnActionExecuting(ActionExecutingContext filterContext)
        {
            filterContext.Controller.ViewBag.CanonicalUrl = "redirectUrl ..... ";

            base.OnActionExecuting(filterContext);
        }
    }

JSON: JavaScript Object Notation

document :{ 
   key: "Value",
   another_key: {
      name: "embedded object"
   },
   some_date: new Date(),
   some_number: 12
}

C# anonymous object

var Document = new { 
   Key= "Value",
   AnotherKey= new {
      Name = "embedded object"
   },
   SomeDate = DateTime.Now(),
   SomeNumber = 12
};

using System.Collections.Generic;

namespace RavenDBSample01.Models
{
    public class Question
    {
        public string By { set; get; }
        public string Title { set; get; }
        public string Content { set; get; }

        public List<Comment> Comments { set; get; }
        public List<Answer> Answers { set; get; }

        public Question()
        {
            Comments = new List<Comment>();
            Answers = new List<Answer>();
        }
    }
}

namespace RavenDBSample01.Models
{
    public class Comment
    {
        public string By { set; get; }
        public string Content { set; get; }
    }
}

namespace RavenDBSample01.Models
{
    public class Answer
    {
        public string By { set; get; }
        public string Content { set; get; }
    }
}

PM> Install-Package RavenDB.Client
PM> Install-Package RavenDB.Server

using Raven.Client.Document;
using RavenDBSample01.Models;

namespace RavenDBSample01
{
    class Program
    {
        static void Main(string[] args)
        {
            using (var store = new DocumentStore
                               {
                                   Url = "http://localhost:8080"
                               }.Initialize())
            {
                using (var session = store.OpenSession())
                {
                    session.Store(new Question
                    {
                        By = "users/Vahid",
                        Title = "Raven Intro",
                        Content = "Test...."
                    });

                    session.SaveChanges();
                }
            }
        }
    }
}

<connectionStrings>
   <add name="ravenDB" connectionString="Url=http://localhost:8080"/>
</connectionStrings>

 The maximum number of requests (30) allowed for this session has been reached.

Raven is ready to process requests. Build 2700, Version 2.5.0 / 6dce79a Server started in 14,438 ms
Data directory: D:\Prog\RavenDBSample01\packages\RavenDB.Server.2.5.2700\tools\Database\System
HostName: <any> Port: 8080, Storage: Esent
Server Url: http://localhost:8080/
Available commands: cls, reset, gc, q
Request #   1: GET     -   514 ms - <system>   - 404 - /docs/Raven/Replication/Destinations
Request #   2: GET     -   763 ms - <system>   - 200 - /queries/?&id=Raven%2FHilo%2Fquestions&id=Raven%2FServerPrefixForHilo
Request #   3: PUT     -   185 ms - <system>   - 201 - /docs/Raven/Hilo/questions
Request #   4: POST    -   103 ms - <system>   - 200 - /bulk_docs
        PUT questions/1

 using (var session = store.OpenSession())
{
  var question1 = session.Load<Question>("questions/1");
  Console.WriteLine(question1.By);
}

using System;
using Raven.Client.Document;
using RavenDBSample01.Models;

namespace RavenDBSample01
{
    class Program
    {
        static void Main(string[] args)
        {
            using (var store = new DocumentStore
                               {
                                   Url = "http://localhost:8080"
                               }.Initialize())
            {
                using (var session = store.OpenSession())
                {
                    var question = new Question
                    {
                        By = "users/Vahid",
                        Title = "Raven Intro",
                        Content = "Test...."
                    };                 
                    question.Answers.Add(new Answer
                    {
                         By = "users/Farid",
                         Content = "بررسی می‌شود"
                    });
                    session.Store(question);

                    session.SaveChanges();
                }

                using (var session = store.OpenSession())
                {
                    var question1 = session.Load<Question>("questions/1");
                    Console.WriteLine(question1.By);
                }
            }
        }
    }
}