ioc.For<IIdentity>()
                     .Use(
                         () =>
                             (HttpContext.Current != null && HttpContext.Current.User != null)
                                 ? HttpContext.Current.User.Identity
                                 : null);

        public ActionResult Create()
        {
            ViewBag.Type = new SelectList(db.Types, "Id", "Title");
            ViewBag.Category = new SelectList(db.Categories, "Id", "Title");
            return View();
        }

        <div>
            نوع
        </div>
        <div>
            @Html.DropDownList("Type", (SelectList)ViewBag.Type, "-- انتخاب ---", new { id = "rdbTyoe" })
            @Html.ValidationMessageFor(model => model.Category)
        </div>

        <div>
            دسته بندی
        </div>
        <div>
            @Html.DropDownList("Category", (SelectList)ViewBag.Category, "-- انتخاب ---", new { id = "rdbCategory"})
            @Html.ValidationMessageFor(model => model.Category)
        </div>

• ابتدا یک تگ option می‌سازیم 
  
• مقادیر مربوطه شامل Id که باید در attribute مورد نظر value قرار گیرد و متن آن که باید به عنوان text باشد را مقدار دهی می‌کنیم
• option آماده شده را به DropDownList دومی (Category ) اضافه می‌کنیم.

بعد از انتخاب :

var result = _db.Users.Where(filteringExpression).ToList();

      protected void btnGetData_Click(object sender, EventArgs e)
      {
          lblResult.Text = (Math.PI * double.Parse(txtRadius.Text) * double.Parse(txtRadius.Text)).ToString();
      }

using System;

namespace MVPTest
{
  public interface ICircleModel
  {
      double GetArea(double radius);
  }

  public class CModel : ICircleModel
  {     
      public double GetArea(double radius)
      {
          return Math.PI * radius * radius;
      }
  }
}

namespace MVPTest
{
  public interface IView
  {
      string RadiusText { get; set; }
      string ResultText { get; set; }
  }
}

namespace MVPTest
{
  public class CPresenter
  {
      IView _view;

      public CPresenter(IView view)
      {
          _view = view;
      }

      public void CalculateCircleArea()
      {
          CModel model = new CModel();
          _view.ResultText = model.GetArea(double.Parse(_view.RadiusText)).ToString();          
      }
  }
}

using System;

namespace MVPTest
{
  public partial class _Default : System.Web.UI.Page, IView
  {
      protected void Page_Load(object sender, EventArgs e)
      {
      }

      public string RadiusText
      {
          get { return txtRadius.Text; }
          set { txtRadius.Text = value; }
      }
      public string ResultText
      {
          get { return lblResult.Text; }
          set { lblResult.Text = value; }
      }

      protected void btnGetData_Click(object sender, EventArgs e)
      {
          CPresenter presenter = new CPresenter(this);
          presenter.CalculateCircleArea();
      }
  }
}

using System.Xml.Linq;

namespace TestModel
{
   public class DynamicTable
   {
       public virtual int Id { get; set; }
       public virtual XDocument Document { get; set; }
   }
}

using FluentNHibernate.Automapping;
using FluentNHibernate.Automapping.Alterations;
using NHibernate.Type;

namespace TestModel
{
   public class DynamicTableMapping : IAutoMappingOverride<DynamicTable>
   {
       public void Override(AutoMapping<DynamicTable> mapping)
       {
           mapping.Id(x => x.Id);
           mapping.Map(x => x.Document).CustomType<XDocType>();
       }
   }
}

   if exists (select * from dbo.sysobjects
                where id = object_id(N'[DynamicTable]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
        drop table [DynamicTable]

   create table [DynamicTable] (
       Id INT IDENTITY NOT NULL,
      Document XML null,
      primary key (Id)
   )

//insert
object savedId = 0;
using (var session = sessionFactory.OpenSession())
{
   using (var tx = session.BeginTransaction())
   {
        var obj = new DynamicTable
        {
            Document = System.Xml.Linq.XDocument.Parse(
                    @"<Doc><Node1>Text1</Node1><Node2>Text2</Node2></Doc>"
                    )
        };
        savedId = session.Save(obj);
        tx.Commit();
    }
}

//simple query
using (var session = sessionFactory.OpenSession())
{
   using (var tx = session.BeginTransaction())
   {
        var entity = session.Get<DynamicTable>(savedId);
        if (entity != null)
        {
           Console.WriteLine(entity.Document.Root.ToString());
        }

        tx.Commit();
    }
}

//advanced query
using (var session = sessionFactory.OpenSession())
{
   using (var tx = session.BeginTransaction())
   {
       var list = session.CreateSQLQuery("select [Document].value('(//Doc/Node1)[1]','nvarchar(255)') from [DynamicTable] where id=:p0")
                               .SetParameter("p0", savedId)
                               .List();

        if (list != null)
        {
             Console.WriteLine(list[0]);
        }

        tx.Commit();
    }
}