using System;
using System.Collections.Generic;
using System.Linq;
using System.Xml.Linq;

namespace LinqToRSS
{
 public static class LanguageExtender
 {
     public static string SafeValue(this XElement input)
     {
         return (input == null) ? string.Empty : input.Value;
     }

     public static DateTime SafeDateValue(this XElement input)
     {
         return (input == null) ? DateTime.MinValue : DateTime.Parse(input.Value);
     }
 }

 public class RssEntry
 {
     public string Title { set; get; }
     public string Description { set; get; }
     public string Link { set; get; }
     public DateTime PublicationDate { set; get; }
     public string Author { set; get; }
     public string BlogName { set; get; }
     public string BlogAddress { set; get; }
 }

 public class Rss
 {
     static XElement selectDate(XElement date1, XElement date2)
     {
         return date1 ?? date2;
     }

     public static List<RssEntry> GetEntries(string feedUrl)
     {
         //applying namespace in an XElement
         XName xn = XName.Get("{http://purl.org/dc/elements/1.1/}creator");//{namespace}root
         XName xn2 = XName.Get("{http://purl.org/dc/elements/1.1/}date");

         var feed = XDocument.Load(feedUrl);
         if (feed.Root == null) return null;

         var items = feed.Root.Element("channel").Elements("item");
         var feedQuery =
             from item in items
             select new RssEntry
                        {
                            Title = item.Element("title").SafeValue(),
                            Description = item.Element("description").SafeValue(),
                            Link = item.Element("link").SafeValue(),
                            PublicationDate =
                                selectDate(item.Element(xn2), item.Element("pubDate")).SafeDateValue(),
                            Author = item.Element(xn).SafeValue(),
                            BlogName = item.Parent.Element("title").SafeValue(),
                            BlogAddress = item.Parent.Element("link").SafeValue()
                        };

         return feedQuery.ToList();
     }
 }

 class Program
 {
     static void Main(string[] args)
     {
         List<RssEntry> entries = Rss.GetEntries("http://weblogs.asp.net/aspnet-team/rss.aspx");
         if (entries != null)
             foreach (var item in entries)
                 Console.WriteLine(item.Title);

         Console.WriteLine("Press a key...");
         Console.ReadKey();
     }
 }
}

<?xml version="1.0" encoding="UTF-8" ?>
<?xml-stylesheet type="text/xsl" href="http://weblogs.asp.net/utility/FeedStylesheets/rss.xsl" media="screen"?>
<rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/" xmlns:wfw="http://wellformedweb.org/CommentAPI/">
<channel>
 <title>Latest Microsoft Blogs</title>
 <link>http://weblogs.asp.net/aspnet-team/default.aspx</link>
 <description />
 <dc:language>en</dc:language>
 <generator>CommunityServer 2007 SP1 (Build: 20510.895)</generator>
 <item>
   <title>Comments on my recent benchmarks.</title>
   <link>http://misfitgeek.com/blog/aspnet/comments-on-my-recent-benchmarks/</link>
   <pubDate>Mon, 10 Aug 2009 23:33:59 GMT</pubDate>
   <guid isPermaLink="false">c06e2b9d-981a-45b4-a55f-ab0d8bbfdc1c:7166225</guid>
   <dc:creator>Misfit Geek: msft</dc:creator>
   <slash:comments>0</slash:comments>
   <wfw:commentRss xmlns:wfw="http://wellformedweb.org/CommentAPI/">http://weblogs.asp.net/aspnet-team/rsscomments.aspx?PostID=7166225</wfw:commentRss>
   <comments>http://misfitgeek.com/blog/aspnet/comments-on-my-recent-benchmarks/#comments</comments>
   <description>Overall I’ve been pretty impressed ...</description>
   <category domain="http://weblogs.asp.net/aspnet-team/archive/tags/ASP.NET/default.aspx">ASP.NET</category>
 </item>
</channel>
</rss>

var items = feed.Root.Element("channel").Elements("item");

XName.Get("{mynamespace}root");
//or
XName.Get("root", "mynamespace");

Private Sub work()
        While True
        End While
End Sub 

Task.Factory.StartNew(Sub() work()) 

Dim lst As New List(Of String) From {"meysam", ".nettips", "vahidnasirii"} 
Parallel.ForEach(lst, Sub(item) Console.WriteLine("name:{0}", item)) 

Dim no(9) As Integer
   For i As Integer = 0 To no.Length - 1
        no(i) = i
   Next
Dim result As IEnumerable(Of Double) = no.AsParallel.Select(Function(q) Math.Pow(q, 3)).OrderBy(Function(q) q)
   For Each items In result
        Console.WriteLine(items)
   Next 

The IControllerFactory 'Server.Helpers.StructureMapControllerFactory' did not return a controller for the name 'admin'

 public class MvcApplication : System.Web.HttpApplication
    {
        protected void Application_Start()
        {
            Database.SetInitializer<EshoppingContext>(null);

            #region Mvc

            AreaRegistration.RegisterAllAreas();
            WebApiConfig.Register(GlobalConfiguration.Configuration);
            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
            RouteConfig.RegisterRoutes(RouteTable.Routes);
            BundleConfig.RegisterBundles(BundleTable.Bundles);
            MvcHandler.DisableMvcResponseHeader = true;

            #endregion

            initStructureMap();
        }
        protected void Application_EndRequest(object sender, EventArgs e)
        {
            ObjectFactory.ReleaseAndDisposeAllHttpScopedObjects();
        }
        static void initStructureMap()
        {
            ObjectFactory.Initialize(x =>
            {
                x.For<IUnitOfWork>().HttpContextScoped().Use(() => new EshoppingContext());
                x.For<IProductCategoryService>().Use<ProductCategoryService>();
                x.For<IProductService>().Use<ProductService>();
                x.For<IPersonService>().Use<PersonService>();
                x.For<IPersonAttachmentService>().Use<PersonAttachmentService>();
                x.For<IPostService>().Use<PostService>();
                x.For<IPostCategoryService>().Use<PostCategoryService>();
                x.For<ISliderItemService>().Use<SliderItemService>();
            });
            ControllerBuilder.Current.SetControllerFactory(new StructureMapControllerFactory());
        }
    }

public class RouteConfig
    {
        public static void RegisterRoutes(RouteCollection routes)
        {
            routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

            routes.MapRoute(
                name: "Default",
                url: "{controller}/{action}/{id}",
                defaults: new
                {
                    controller = MVC.Home.Name,
                    action = MVC.Home.ActionNames.Index,
                    id = UrlParameter.Optional
                },
                namespaces: new[] { "Server.Main.Controllers" }
            );
        }
    }

public class StructureMapControllerFactory : DefaultControllerFactory
    {
        protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
        {
            if (controllerType == null)
            {
                return null;
            }
            return ObjectFactory.GetInstance(controllerType) as Controller;
        }
    }

public class PostToXml
    {
        
        public int PostId { get; set; }

        public string title { get; set; }

        public string link { get; set; }
        
        public string description { get; set; }

        public Nullable<DateTime> pubDate { get; set; }

      
    }

       public ContentResult RSS()
        {
            
            var items = GetRssFeed();
            var rss = new XDocument(new XDeclaration("1.0", "utf-8", "yes"),
              new XElement("rss",
                new XAttribute("version", "2.0"),
                  new XElement("channel",
                    new XElement("title", "آخرین مطالب سایت"),
                    new XElement("link", "http://" + Request.Url.Host+"/rss"),
                    new XElement("description", "آخرین مطالب سایت من"),
                    new XElement("copyright","(c)" + DateTime.Now.Year + ", نام سایت من.تمامی حقوق محفوظ است"),
                  from item in items
                  select
                  new XElement("item",
                    new XElement("title", item.title),
                    new XElement("description", item.description),
                    new XElement("link", item.link),
                    new XElement("pubDate", item.pubDate)

                  )
                )
              )
            );
            return Content(rss.ToString(), "text/xml");
        }



        public ContentResult Sitemap()
        {
            XNamespace ns = "http://www.sitemaps.org/schemas/sitemap/0.9";
            var items = GetLinks();
            var sitemap = new XDocument(new XDeclaration("1.0", "utf-8", "yes"),
                new XElement(ns + "urlset",
                    from item in items
                    select
                    new XElement("url",
                      new XElement("loc", item.link),
                      new XElement("changefreq", "monthly"),
                      new XElement("priority", "0.5")
                      )
                    )
                  );
            return Content(sitemap.ToString(), "text/xml");
        }


        public IEnumerable<PostToXml> GetRssFeed()
        {
          // یک کوئری که لیستی از تایپ مشخص شده به ما بدهد
        }

         public IEnumerable<PostToXml> GetLinks()
        {
            // یک کوئری که لیستی از تایپ مشخص شده به ما بدهد
        }

routes.MapRoute(
              "Sitemap", "sitemap",
              new { controller = "XML", action = "Sitemap" });
 routes.MapRoute(
              "RSS", "rss",
               new { controller = "XML", action = "RSS" });

http://domain.com/rss
http://domain.com/sitemap  

using System;
using System.ComponentModel.DataAnnotations;

namespace MvcApplication9.Models
{
    public class Customer
    {
        public int Id { set; get; }

        [Required(ErrorMessage = "Name is required.")]
        [StringLength(50)]
        public string Name { set; get; }

        [Display(Name = "Email address")]
        [Required(ErrorMessage = "Email address is required.")]
        [RegularExpression(@"\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*",
                           ErrorMessage = "Please enter a valid email address.")]
        public string Email { set; get; }

        [Range(0, 10)]
        [Required(ErrorMessage = "Rating is required.")]
        public double Rating { set; get; }

        [Display(Name = "Start date")]
        [Required(ErrorMessage = "Start date is required.")]
        public DateTime StartDate { set; get; }
    }
}

using System.Web.Mvc;
using MvcApplication9.Models;

namespace MvcApplication9.Controllers
{
    public class CustomerController : Controller
    {
        [HttpGet]
        public ActionResult Create()
        {
            var customer = new Customer();
            return View(customer);
        }

        [HttpPost]
        public ActionResult Create(Customer customer)
        {
            if (this.ModelState.IsValid)
            {
                //todo: save data
                return Redirect("/");
            }
            return View(customer);
        }
    }
}

<appSettings>
    <add key="ClientValidationEnabled" value="true"/>

@{ Html.EnableClientValidation(false); }

<script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script>

@using (Html.BeginForm()) {
    @Html.ValidationSummary(true)
    <fieldset>
        <legend>Customer</legend>

        <div class="editor-label">
            @Html.LabelFor(model => model.Name)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.Name)
            @Html.ValidationMessageFor(model => model.Name)
        </div>

<input data-val="true" data-val-required="The Birthday field is required." id="Birthday" name="Birthday" type="text" value="" />

<script src="../../Scripts/customvaildation.js" type="text/javascript"></script>

using System;
using System.ComponentModel.DataAnnotations;

namespace MvcApplication9.CustomValidators
{
    public class MyDateValidator : ValidationAttribute
    {
        public int MinYear { set; get; }

        public override bool IsValid(object value)
        {
            if (value == null) return false;

            var date = (DateTime)value;
            if (date > DateTime.Now || date < new DateTime(MinYear, 1, 1))
                return false;

            return true;
        }
    }
}

[Display(Name = "Start date")]
[Required(ErrorMessage = "Start date is required.")]
[MyDateValidator(MinYear = 2000,
                         ErrorMessage = "Please enter a valid date.")]
public DateTime StartDate { set; get; }

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using MvcApplication9.CustomValidators;

namespace MvcApplication9.Models
{
    public class Customer : IValidatableObject
    {
        //... same as before

        public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
        {
            var fields = new[] { "StartDate" };
            if (StartDate > DateTime.Now || StartDate < new DateTime(2000, 1, 1))
                yield return new ValidationResult("Please enter a valid date.", fields);

            if (Rating > 4 && StartDate < new DateTime(2003, 1, 1))
                yield return new ValidationResult("Accepted date should be greater than 2003", fields);
        }
    }
}

protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
    var info = validationContext.ObjectType.GetProperty("Rating");
    //...
    return ValidationResult.Success;
}

using System;
using System.ComponentModel.DataAnnotations;
using System.Web.Mvc;
using System.Collections.Generic;

namespace MvcApplication9.CustomValidators
{
    public class MyDateValidator : ValidationAttribute, IClientValidatable
    {
       // ... same as before

        public IEnumerable<ModelClientValidationRule> GetClientValidationRules(
                    ModelMetadata metadata, 
                    ControllerContext context)
        {
            var rule = new ModelClientValidationRule
            {
                ValidationType = "mydatevalidator",
                ErrorMessage = FormatErrorMessage(metadata.GetDisplayName())
            };
            yield return rule;
        }
    }
}

/// <reference path="jquery-1.5.1-vsdoc.js" />
/// <reference path="jquery.validate-vsdoc.js" />
/// <reference path="jquery.validate.unobtrusive.js" />

jQuery.validator.addMethod("mydatevalidator",
 function (value, element, param) {
     return Date.parse(value) < new Date();
});

jQuery.validator.unobtrusive.adapters.addBool("mydatevalidator");

<script src="@Url.Content("~/Scripts/customvaildation.js")" type="text/javascript"></script>

1. .field-validation-error
2. .field-validation-valid
3. .input-validation-error
4. .input-validation-valid
5. .validation-summary-errors
6. .validation-summary-valid

[MetadataType(typeof(CustomerMetadata))]
public partial class Customer
{
    class CustomerMetadata
     {

     }
}

public partial class Customer : IValidatableObject
{

[Required(ErrorMessage = "Name is required.")]
[StringLength(50)]
[System.Web.Mvc.Remote(action: "CheckUserNameAndEmail",
                               controller: "Customer",
                               AdditionalFields = "Email",
                               HttpMethod = "POST",
                               ErrorMessage = "Username is not available.")]
public string Name { set; get; }

[HttpPost]
[OutputCache(Location = OutputCacheLocation.None, NoStore = true)]
public ActionResult CheckUserNameAndEmail(string name, string email)
{
      if (name.ToLowerInvariant() == "vahid") return Json(false);
      if (email.ToLowerInvariant() == "name@site.com") return Json(false);
      //...
      return Json(true);
}

using System.ComponentModel.DataAnnotations;

namespace MvcApplication9.Helper
{
    public static class ValidationHelper
    {
        public static bool TryValidateObject(this object instance)
        {
            return Validator.TryValidateObject(instance, new ValidationContext(instance, null, null), null);
        }
    }
}