PM> Install-Package Microsoft.AspNet.WebApi.OwinSelfHost

using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;
using System.Web.Http;

namespace WebApiSelfHostTests
{
    public class UsersController : ApiController
    {
        public IEnumerable<User> GetAllUsers()
        {
            return new[]
            {
                new User{ Id = 1, Name = "User 1", Type = UserType.Admin },
                new User{ Id = 2, Name = "User 2", Type = UserType.User }
            };
        }

        public async Task<HttpResponseMessage> Post(HttpRequestMessage request)
        {
            var jsonContent = await request.Content.ReadAsStringAsync();
            Console.WriteLine("JsonContent (Server Side): {0}", jsonContent);
            return new HttpResponseMessage(HttpStatusCode.Created);
        }
    }
}

namespace WebApiSelfHostTests
{
    public enum UserType
    {
        User,
        Admin,
        Writer
    }

    public class User
    {
        public int Id { set; get; }
        public string Name { set; get; }
        public UserType Type { set; get; }
    }
}

using System.Web.Http;
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
using Owin;

namespace WebApiSelfHostTests
{
    /// <summary>
    /// PM> Install-Package Microsoft.AspNet.WebApi.OwinSelfHost
    /// </summary>
    public class Startup
    {
        public void Configuration(IAppBuilder appBuilder)
        {
            var config = new HttpConfiguration();
            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
                );

            appBuilder.UseWebApi(config);
        }
    }
}

 var server = WebApp.Start<Startup>(url: BaseAddress);


Console.WriteLine("Press Enter to quit.");
Console.ReadLine();
server.Dispose();

 using (var client = new HttpClient())
{
   var response = client.GetAsync(BaseAddress + "api/users").Result;
   Console.WriteLine("Response: {0}", response);
   Console.WriteLine("JsonContent (Client Side): {0}", response.Content.ReadAsStringAsync().Result);
}

 JsonContent (Client Side): [{"Id":1,"Name":"User 1","Type":1},{"Id":2,"Name":"User 2","Type":0}]

    public class Startup
    {
        public void Configuration(IAppBuilder appBuilder)
        {
            var config = new HttpConfiguration();
            config.Formatters.JsonFormatter.SerializerSettings = new JsonSerializerSettings
            {
                Converters = { new StringEnumConverter() }
            };

 JsonContent (Client Side): [{"Id":1,"Name":"User 1","Type":"Admin"},{"Id":2,"Name":"User 2","Type":"User"}]

var user = new User
{
   Id = 1,
   Name = "User 1",
   Type = UserType.Writer
};

var client = new HttpClient();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

var response = client.PostAsJsonAsync(BaseAddress + "api/users", user).Result;
Console.WriteLine("Response: {0}", response);

 JsonContent (Server Side): {"Id":1,"Name":"User 1","Type":2}

            var jsonMediaTypeFormatter = new JsonMediaTypeFormatter
            {
                SerializerSettings = new JsonSerializerSettings
                {
                    Converters = { new StringEnumConverter() }
                }
            };
            var response = client.PostAsync(BaseAddress + "api/users", user, jsonMediaTypeFormatter).Result;
            Console.WriteLine("Response: {0}", response);

 JsonContent (Server Side): {"Id":1,"Name":"User 1","Type":"Writer"}

public class UserModel
{
    public int Id { get; set; }
 
    [Required(ErrorMessage = "(*)")]
    [Display(Name = "نام")]
    [StringLength(maximumLength: 10, MinimumLength = 3, ErrorMessage = "نام باید حداقل 3 و حداکثر 10 حرف باشد")]
    public string FirstName { get; set; }
 
    [Required(ErrorMessage = "(*)")]
    [Display(Name = "نام خانوادگی")]
    [StringLength(maximumLength: 10, MinimumLength = 3, ErrorMessage = "نام خانوادگی باید حداقل 3 و حداکثر 10 حرف باشد")]
    public string LastName { get; set; }
}

public class UserViewModel
{
      public string FirstName { get; set; }
      public string LastName { get; set; }
}

public class MappedMetadataProvider : DataAnnotationsModelMetadataProvider
{
    private readonly IConfigurationProvider _mapper;
 
    public MappedMetadataProvider(IConfigurationProvider mapper)
    {
        _mapper = mapper;
    }
 
    protected override ModelMetadata CreateMetadata(
        IEnumerable<Attribute> attributes,
        Type containerType,
        Func<object> modelAccessor,
        Type modelType,
        string propertyName)
    {
        var mappedAttributes =
            containerType == null ?
            attributes :
            _mapper.GetMappedAttributes(containerType, propertyName, attributes.ToList());
        return base.CreateMetadata(mappedAttributes, containerType, modelAccessor, modelType, propertyName);
    }
}

public class MappedValidatorProvider : DataAnnotationsModelValidatorProvider
{
    private readonly IConfigurationProvider _mapper;
 
    public MappedValidatorProvider(IConfigurationProvider mapper)
    {
        _mapper = mapper;
    }
 
    protected override IEnumerable<ModelValidator> GetValidators(
        ModelMetadata metadata,
        ControllerContext context,
        IEnumerable<Attribute> attributes)
    {
 
        var mappedAttributes =
            metadata.ContainerType == null ?
            attributes :
            _mapper.GetMappedAttributes(metadata.ContainerType, metadata.PropertyName, attributes.ToList());
        return base.GetValidators(metadata, context, mappedAttributes);
    }
}

public static class AutoMapperExtensions
{
    public static IEnumerable<Attribute> GetMappedAttributes(
        this IConfigurationProvider mapper,
        Type viewModelType,
        string viewModelPropertyName,
        IList<Attribute> existingAttributes)
    {
        if (viewModelType != null)
        {
            foreach (var typeMap in mapper.GetAllTypeMaps().Where(i => i.DestinationType == viewModelType))
            {
                var propertyMaps = typeMap.GetPropertyMaps()
                    .Where(propertyMap => !propertyMap.IsIgnored() && propertyMap.SourceMember != null)
                    .Where(propertyMap => propertyMap.DestinationProperty.Name == viewModelPropertyName);
 
                foreach (var propertyMap in propertyMaps)
                {
                    foreach (Attribute attribute in propertyMap.SourceMember.GetCustomAttributes(true))
                    {
                        if (existingAttributes.All(i => i.GetType() != attribute.GetType()))
                        {
                            yield return attribute;
                        }
                    }
                }
            }
        }
 
        if (existingAttributes == null)
        {
            yield break;
        }
 
        foreach (var attribute in existingAttributes)
        {
            yield return attribute;
        }
    }
}

protected void Application_Start()
{
    AreaRegistration.RegisterAllAreas();
    WebApiConfig.Register(GlobalConfiguration.Configuration);
    FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
    RouteConfig.RegisterRoutes(RouteTable.Routes); 
 
    Mappings.RegisterMappings();
    ModelMetadataProviders.Current = new MappedMetadataProvider(Mapper.Engine.ConfigurationProvider);
 
    var modelValidatorProvider = ModelValidatorProviders.Providers
        .Single(provider => provider is DataAnnotationsModelValidatorProvider);
    ModelValidatorProviders.Providers.Remove(modelValidatorProvider);
    ModelValidatorProviders.Providers.Add(new MappedValidatorProvider(Mapper.Engine.ConfigurationProvider));
}

public class HomeController : Controller
{
    public ActionResult Index()
    {
        var model = new UserModel { FirstName = "و", Id = 1, LastName = "ن" };
        var viewModel = Mapper.Map<UserViewModel>(model);
        return View(viewModel);
    }
 
    [HttpPost]
    public ActionResult Index(UserViewModel data)
    {
        return View(data);
    }
}

@model Sample12.ViewModels.UserViewModel
 
@using (Html.BeginForm("Index", "Home", FormMethod.Post, htmlAttributes: new { @class = "form-horizontal", role = "form" }))
{
    <div class="row">
        <div class="form-group">
            @Html.LabelFor(d => d.FirstName, htmlAttributes: new { @class = "col-md-2 control-label" })
            <div class="col-md-10">
                @Html.TextBoxFor(d => d.FirstName)
                @Html.ValidationMessageFor(d => d.FirstName)
            </div>
        </div>
        <div class="form-group">
            @Html.LabelFor(d => d.LastName, htmlAttributes: new { @class = "col-md-2 control-label" })
            <div class="col-md-10">
                @Html.TextBoxFor(d => d.LastName)
                @Html.ValidationMessageFor(d => d.LastName)
            </div>
        </div>
        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="ارسال" class="btn btn-default" />
            </div>
        </div>
    </div>
}

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));

قدم بعدی افزودن کدهای سمت کلاینت برای SignalR می‌باشد. دقت داشته باشید که کدهایی که در ادامه مشاهده خواهید کرد دقیقاً مطابق دستورالمعل‌هایی است که قبلاً مشاهده کرده‌اید. برای اینکار داخل کلاس MainActivity.java کدهای زیر را اضافه کنید:

Platform.loadPlatformComponent( new AndroidPlatformComponent() );
HubConnection connection = new HubConnection(DEFAULT_SERVER_URL);
HubProxy hub = connection.createHubProxy("ChatHub");
connection.error(new ErrorCallback() {
    
    @Override
    public void onError(final Throwable error) {
        runOnUiThread(new Runnable() {
            public void run() {
                Toast.makeText(getApplicationContext(), error.getMessage(), Toast.LENGTH_LONG).show();
            }
        });
        
    }
});
hub.subscribe(new Object() {
    @SuppressWarnings("unused")
    public void messageReceived(final String name, final String message) {
        
        runOnUiThread(new Runnable() {
            public void run() {
                Toast.makeText(getApplicationContext(), name + ": " + message, Toast.LENGTH_LONG).show();
            }
        });
    }
});
connection.start()
.done(new Action<Void>() {
    
    @Override
    public void run(Void obj) throws Exception {
        runOnUiThread(new Runnable() {
            public void run() {
                Toast.makeText(getApplicationContext(), "Done Connecting!", Toast.LENGTH_LONG).show();
            }
        });
    }
});
connection.received(new MessageReceivedHandler() {
    @Override
    public void onMessageReceived(final JsonElement json) {
        runOnUiThread(new Runnable() {
            public void run() {
                JsonObject jsonObject = json.getAsJsonObject();
                JsonArray jsonArray =jsonObject.getAsJsonArray("A");
                Toast.makeText(getApplicationContext(), jsonArray.get(0).getAsString() + ": " + jsonArray.get(1).getAsString(), Toast.LENGTH_LONG).show();
            }
        });
    }
});

همانطور که مشاهده می‌کنید توسط قطعه کد زیر SKD مربوطه در نسخه‌های قدیمی اندروید نیز بدون مشکل کار خواهد کرد:

Platform.loadPlatformComponent( new AndroidPlatformComponent() );

در ادامه توسط متد createHubProxy ارجاعی به هابی که در سمت سرور ایجاد کردیم، داده‌ایم:

HubProxy hub = connection.createHubProxy("ChatHub");

در ادامه نیز توسط یک روال رویدادگردان وضعیت اتصال را چک کرده‌ایم. یعنی در زمان بروز خطا در نحوه ارتباط یک پیام بر روی صفحه نمایش داده می‌شود:

connection.error(new ErrorCallback() {
    
    @Override
    public void onError(final Throwable error) {
        runOnUiThread(new Runnable() {
            public void run() {
                Toast.makeText(getApplicationContext(), error.getMessage(), Toast.LENGTH_LONG).show();
            }
        });
        
    }
});

hub.subscribe(new Object() {
    @SuppressWarnings("unused")
    public void messageReceived(final String name, final String message) {
        
        runOnUiThread(new Runnable() {
            public void run() {
                Toast.makeText(getApplicationContext(), name + ": " + message, Toast.LENGTH_LONG).show();
            }
        });
    }
});

connection.start()
.done(new Action<Void>() {
    
    @Override
    public void run(Void obj) throws Exception {
        runOnUiThread(new Runnable() {
            public void run() {
                Toast.makeText(getApplicationContext(), "Done Connecting!", Toast.LENGTH_LONG).show();
            }
        });
    }
});

connection.received(new MessageReceivedHandler() {
    @Override
    public void onMessageReceived(final JsonElement json) {
        runOnUiThread(new Runnable() {
            public void run() {
                JsonObject jsonObject = json.getAsJsonObject();
                JsonArray jsonArray =jsonObject.getAsJsonArray("A");
                Toast.makeText(getApplicationContext(), jsonArray.get(0).getAsString() + ": " + jsonArray.get(1).getAsString(), Toast.LENGTH_LONG).show();
            }
        });
    }
});

var result = 
    from product in dbContext.Products
    where product.Category.Name == "Toys"
    where product.Price >= 2.50
    select product.Name;

• Fluent Syntax : 

var result = dbContext.Products
    .Where(p => p.Category.Name == "Toys" && p.Price >= 250)
    .Select(p => p.Name);

    public class Student
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public string Field1 { get; set; }
        public string Field2 { get; set; }
        public string Field3 { get; set; }


        public static IEnumerable<Student> GetStudentSource()
        {
            for (int i = 0; i < 10; i++)
            {
                yield return new Student
                                 {
                                     Id = i,
                                     Name = "Name " + i,
                                     Field1 = "Field1 " + i,
                                     Field2 = "Field2 " + i,
                                     Field3 = "Field3 " + i
                                 };
            }
        }
    }

    public class Program
    {
        private static void Main(string[] args)
        {
            System.Console.WriteLine("Specify the desired fields : ");
            string fields = System.Console.ReadLine();
            IEnumerable<Student> students = Student.GetStudentSource();
            IQueryable output = students.AsQueryable().Select(string.Format("new({0})", fields));
            foreach (object item in output)
            {
                System.Console.WriteLine(item);
            }
          
            System.Console.ReadKey();
        }
  
    }

    public  class SelectBuilder <T>
    {
        public static Func<T, T> CreateNewStatement(string fields)
        {
            // input parameter "o"
            var xParameter = Expression.Parameter(typeof(T), "o");


            // new statement "new T()"
            var xNew = Expression.New(typeof(T));

            // create initializers
            var bindings = fields.Split(',').Select(o => o.Trim())
                .Select(o =>
                {

                    // property "Field1"
                    var property = typeof(T).GetProperty(o);

                    // original value "o.Field1"
                    var xOriginal = Expression.Property(xParameter, property);

                    // set value "Field1 = o.Field1"
                    return Expression.Bind(property, xOriginal);
                }
            ).ToList();

            // initialization "new T { Field1 = o.Field1, Field2 = o.Field2 }"
            var xInit = Expression.MemberInit(xNew, bindings);

            // expression "o => new T { Field1 = o.Field1, Field2 = o.Field2 }"
            var lambda = Expression.Lambda<Func<T, T>>(xInit, xParameter);

            // compile to Func<T, T>
            return lambda.Compile();
        }
    }

       IEnumerable<Student> result = students.Select(SelectBuilder<Student>.CreateNewStatement("Field1, Field2")).ToList();

            foreach (Student student in result)
            {
                System.Console.WriteLine(student.Field1);
            }

ابتدا فیلد‌های انتخابی کاربر که با "," جدا شده اند به ورودی پاس داده می‌شود سپس یک statement  خالی ایجاد می‌شود : 

o=>new Student()

public class Car
{
    public string Id { get; set; }

public class Car
{
   public string CarId { get; set; }

public class Car
{
   [Key]
   public string LicensePlate { get; set; }

public class MyContext : DbContext
{
    public DbSet<Car> Cars { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
         modelBuilder.Entity<Car>()
                 .HasKey(c => c.LicensePlate);
    }
 }

{
   "dependencies": {
          "System.ComponentModel.Annotations": "4.1.0"
   }
}

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
   modelBuilder.Entity<Car>()
                       .HasKey(c => new { c.State, c.LicensePlate });
}

public class Blog
{
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int BlogId { get; set; }

    public string Url { get; set; }
}

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<Blog>()
           .Property(b => b.BlogId)
           .ValueGeneratedNever();
}

public class Blog
{
   public int BlogId { get; set; }
   public string Url { get; set; }

   [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
   public DateTime Inserted { get; set; }
}

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<Blog>()
           .Property(b => b.Inserted)
           .ValueGeneratedOnAdd();
}

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<Blog>()
        .Property(b => b.Inserted)
        .HasDefaultValueSql("getdate()");
}

public class Blog
{
    public int BlogId { get; set; }
    public string Url { get; set; }

    [DatabaseGenerated(DatabaseGeneratedOption.Computed)]
    public DateTime LastUpdated { get; set; }
}

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<Blog>()
       .Property(b => b.LastUpdated)
       .ValueGeneratedOnAddOrUpdate();
}

public class Person
{
    public int PersonId { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string DisplayName { get; set; }
}

public class MyContext : DbContext
{
    public DbSet<Person> People { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
          modelBuilder.Entity<Person>()
              .Property(p => p.DisplayName)
               .HasComputedColumnSql("[LastName] + ', ' + [FirstName]");
     }
 }

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
     modelBuilder.HasSequence<int>("OrderNumbers", schema: "shared") 
           .StartsAt(1000).IncrementsBy(5);

     modelBuilder.Entity<Order>()
         .Property(o => o.OrderNo)
         .HasDefaultValueSql("NEXT VALUE FOR shared.OrderNumbers");
}

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.HasSequence<int>("PrimaryKeyWithSequenceSequence");
    modelBuilder.Entity<PrimaryKeyWithSequence>(entity =>
     {
       entity.Property(e => e.PrimaryKeyWithSequenceId).HasDefaultValueSql("NEXT VALUE FOR [PrimaryKeyWithSequenceSequence]");
     });
}

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
      modelBuilder.Entity<Blog>()
          .HasIndex(b => b.Url)
          .HasName("Index_Url");

 modelBuilder.Entity<Blog>().HasIndex(b => b.Url).HasName("Index_Url").IsUnique();

modelBuilder.Entity<Person>()
   .HasIndex(idx => new { idx.FirstName, idx.LastName })
   .IsUnique();

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
   modelBuilder.Entity<Car>()
     .HasAlternateKey(c => c.LicensePlate)
     .HasName("AlteranteKey_LicensePlate");
}

modelBuilder.Entity<Person>()
     .HasAlternateKey(x => new { x.FirstName, x.LastName });

 table.UniqueConstraint("AK_Persons_FirstName_LastName", x => new { x.FirstName, x.LastName });