public class Order { 
    public decimal Price() { 
        var primaryBasePrice = 10000; 
        var branchDiscountBasePrice = 9000; 
        var taxPercentage = 9; 
        // calculate price 
    } 
}

public class Order 
{ 
    public decimal Price() { 
        return new PriceCalculator(this).Compute(); 
    } 
} 
public class PriceCalculator 
{ 
    private Order orderInstance ;
    public PriceCalculator(Order order) 
    { 
        orderInstance = order;
    } 
    public decimal Compute() 
    { 
        var primaryBasePrice = 10000; 
        var branchDiscountBasePrice = 9000; 
        var taxPercentage = 9; 
        // calculate price 
    } 
}

internal class Program
{
    private HttpClient _client;
    private Customer _bush, _obama;
    private Phone _whiteHousePhone, _bushMobilePhone, _obamaMobilePhone;
    private HttpResponseMessage _response;

    private static void Main()
    {
        Task t = Run();
        t.Wait();
        Console.WriteLine("\nPress <enter> to continue...");
        Console.ReadLine();
    }

    private static async Task Run()
    {
        var program = new Program();
        program.ServiceSetup();
        // do not proceed until clean-up completes
        await program.CleanupAsync();
        program.CreateFirstCustomer();
        // do not proceed until customer is added
        await program.AddCustomerAsync();
        program.CreateSecondCustomer();
        // do not proceed until customer is added
        await program.AddSecondCustomerAsync();
        // do not proceed until customer is removed
        await program.RemoveFirstCustomerAsync();
        // do not proceed until customers are fetched
        await program.FetchCustomersAsync();
    }

    private void ServiceSetup()
    {
        // set up infrastructure for Web API call
        _client = new HttpClient { BaseAddress = new Uri("http://localhost:62799/") };
        // add Accept Header to request Web API content negotiation to return resource in JSON format
        _client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue
        ("application/json"));
    }
    private async Task CleanupAsync()
    {
        // call the cleanup method from the service
        _response = await _client.DeleteAsync("api/customer/cleanup/");
    }

    private void CreateFirstCustomer()
    {
        // create customer #1 and two phone numbers
        _bush = new Customer
        {
            Name = "George Bush",
            Company = "Ex President",
            // set tracking state to 'Add' to generate a SQL Insert statement
            TrackingState = TrackingState.Add,
        };
        _whiteHousePhone = new Phone
        {
            Number = "212 222-2222",
            PhoneType = "White House Red Phone",
            // set tracking state to 'Add' to generate a SQL Insert statement
            TrackingState = TrackingState.Add,
        };
        _bushMobilePhone = new Phone
        {
            Number = "212 333-3333",
            PhoneType = "Bush Mobile Phone",
            // set tracking state to 'Add' to generate a SQL Insert statement
            TrackingState = TrackingState.Add,
        };
        _bush.Phones.Add(_whiteHousePhone);
        _bush.Phones.Add(_bushMobilePhone);
    }

    private async Task AddCustomerAsync()
    {
        // construct call to invoke UpdateCustomer action method in Web API service
        _response = await _client.PostAsync("api/customer/updatecustomer/", _bush, new JsonMediaTypeFormatter());
        if (_response.IsSuccessStatusCode)
        {
            // capture newly created customer entity from service, which will include
            // database-generated Ids for all entities
            _bush = await _response.Content.ReadAsAsync<Customer>();
            _whiteHousePhone = _bush.Phones.FirstOrDefault(x => x.CustomerId == _bush.CustomerId);
            _bushMobilePhone = _bush.Phones.FirstOrDefault(x => x.CustomerId == _bush.CustomerId);
            Console.WriteLine("Successfully created Customer {0} and {1} Phone Numbers(s)",
            _bush.Name, _bush.Phones.Count);
            foreach (var phoneType in _bush.Phones)
            {
                Console.WriteLine("Added Phone Type: {0}", phoneType.PhoneType);
            }
        }
        else
            Console.WriteLine("{0} ({1})", (int)_response.StatusCode, _response.ReasonPhrase);
    }

    private void CreateSecondCustomer()
    {
        // create customer #2 and phone numbers
        _obama = new Customer
        {
            Name = "Barack Obama",
            Company = "President",
            // set tracking state to 'Add' to generate a SQL Insert statement
            TrackingState = TrackingState.Add,
        };
        _obamaMobilePhone = new Phone
        {
            Number = "212 444-4444",
            PhoneType = "Obama Mobile Phone",
            // set tracking state to 'Add' to generate a SQL Insert statement
            TrackingState = TrackingState.Add,
        };
        // set tracking state to 'Modifed' to generate a SQL Update statement
        _whiteHousePhone.TrackingState = TrackingState.Update;
        _obama.Phones.Add(_obamaMobilePhone);
        _obama.Phones.Add(_whiteHousePhone);
    }

    private async Task AddSecondCustomerAsync()
    {
        // construct call to invoke UpdateCustomer action method in Web API service
        _response = await _client.PostAsync("api/customer/updatecustomer/", _obama, new JsonMediaTypeFormatter());
        if (_response.IsSuccessStatusCode)
        {
            // capture newly created customer entity from service, which will include
            // database-generated Ids for all entities
            _obama = await _response.Content.ReadAsAsync<Customer>();
            _whiteHousePhone = _bush.Phones.FirstOrDefault(x => x.CustomerId == _obama.CustomerId);
            _bushMobilePhone = _bush.Phones.FirstOrDefault(x => x.CustomerId == _obama.CustomerId);
            Console.WriteLine("Successfully created Customer {0} and {1} Phone Numbers(s)",
            _obama.Name, _obama.Phones.Count);
            foreach (var phoneType in _obama.Phones)
            {
                Console.WriteLine("Added Phone Type: {0}", phoneType.PhoneType);
            }
        }
        else
            Console.WriteLine("{0} ({1})", (int)_response.StatusCode, _response.ReasonPhrase);
    }

    private async Task RemoveFirstCustomerAsync()
    {
        // remove George Bush from underlying data store.
        // first, fetch George Bush entity, demonstrating a call to the
        // get action method on the service while passing a parameter
        var query = "api/customer/" + _bush.CustomerId;
        _response = _client.GetAsync(query).Result;

        if (_response.IsSuccessStatusCode)
        {
            _bush = await _response.Content.ReadAsAsync<Customer>();
            // set tracking state to 'Remove' to generate a SQL Delete statement
            _bush.TrackingState = TrackingState.Remove;
            // must also remove bush's mobile number -- must delete child before removing parent
            foreach (var phoneType in _bush.Phones)
            {
                // set tracking state to 'Remove' to generate a SQL Delete statement
                phoneType.TrackingState = TrackingState.Remove;
            }
            // construct call to remove Bush from underlying database table
            _response = await _client.PostAsync("api/customer/updatecustomer/", _bush, new JsonMediaTypeFormatter());
            if (_response.IsSuccessStatusCode)
            {
                Console.WriteLine("Removed {0} from database", _bush.Name);
                foreach (var phoneType in _bush.Phones)
                {
                    Console.WriteLine("Remove {0} from data store", phoneType.PhoneType);
                }
            }
            else
                Console.WriteLine("{0} ({1})", (int)_response.StatusCode, _response.ReasonPhrase);
        }
        else
        {
            Console.WriteLine("{0} ({1})", (int)_response.StatusCode, _response.ReasonPhrase);
        }
    }

    private async Task FetchCustomersAsync()
    {
        // finally, return remaining customers from underlying data store
        _response = await _client.GetAsync("api/customer/");
        if (_response.IsSuccessStatusCode)
        {
            var customers = await _response.Content.ReadAsAsync<IEnumerable<Customer>>();
            foreach (var customer in customers)
            {
                Console.WriteLine("Customer {0} has {1} Phone Numbers(s)",
                customer.Name, customer.Phones.Count());
                foreach (var phoneType in customer.Phones)
                {
                    Console.WriteLine("Phone Type: {0}", phoneType.PhoneType);
                }
            }
        }
        else
        {
            Console.WriteLine("{0} ({1})", (int)_response.StatusCode, _response.ReasonPhrase);
        }
    }
}

SELECT EMPLOYEEKEY,FIRSTNAME,LASTNAME, MIDDLENAME,TITLE,HIREDATE, BIRTHDATE,EMAILADDRESS,PHONE,GENDER FROM DBO.DIMEMPLOYEE WHERE DEPARTMENTNAME=@DEPARTMENTNAME AND GENDER=@GENDER

@Html.ActionLink("About us", "Index", "About")

<a href="/About">About us</a>

@using MvcApplication5.Models
@model MvcApplication5.Models.Products
@{
    ViewBag.Title = "Index";
}
@helper GetProductsList(List<Product> products)
    {
    <ul>
        @foreach (var item in products)
        {
            <li>@Html.ActionLink(item.Name, "Details", new { id = item.ProductNumber })</li>
        }
    </ul>
}
<h2>Index</h2>

@GetProductsList(@Model)

http://localhost/Home/Details/D123

using System.Linq;
using System.Web.Mvc;
using MvcApplication5.Models;

namespace MvcApplication5.Controllers
{
    public class HomeController : Controller
    {
        public ActionResult Index()
        {
            var products = new Products();
            return View(products);
        }

        public ActionResult Details(string id)
        {
            var product = new Products().FirstOrDefault(x => x.ProductNumber == id);
            if (product == null)
                return View("Error");
            return View(product);
        }
    }
}

@model MvcApplication5.Models.Product

@{
    ViewBag.Title = "Details";
}

<h2>Details</h2>

<fieldset>
    <legend>Product</legend>

    <div class="display-label">ProductNumber</div>
    <div class="display-field">@Model.ProductNumber</div>

    <div class="display-label">Name</div>
    <div class="display-field">@Model.Name</div>

    <div class="display-label">Price</div>
    <div class="display-field">@String.Format("{0:F}", Model.Price)</div>
</fieldset>
<p>
    @Html.ActionLink("Edit", "Edit", new { /* id=Model.PrimaryKey */ }) |
    @Html.ActionLink("Back to List", "Index")
</p>

'System.Web.WebPages.Html.HtmlHelper' does not contain a definition for 'ActionLink' 

@using System.Web.Mvc
@using System.Web.Mvc.Html

@using MvcApplication5.Models

@helper GetProductsList(WebViewPage page, List<Product> products)
    {
    <ul>
        @foreach (var item in products)
        {
            <li> @page.Html.ActionLink(item.Name, "Details", new { id = item.ProductNumber })</li>
        }
    </ul>
}

@MyHelpers.GetProductsList(this, @Model)

http://localhost/Home/Details/%D9%85%D9%82%D8%AF%D8%A7%D8%B1%20%D9%8A%D9%83

<li><a href="/Home/Details/مقدار یک">Super Fast Bike</a></li>

@helper EmitCleanUnicodeUrl(MvcHtmlString data)
{
    @Html.Raw(HttpUtility.UrlDecode(data.ToString()))
}

@helper GetProductsList(List<Product> products)
    {
    <ul>
        @foreach (var item in products)
        {
            <li>@EmitCleanUnicodeUrl(@Html.ActionLink(item.Name, "Details", new { id = item.ProductNumber }))</li>
        }
    </ul>
}