ASP.NET

this.Dispatcher.BeginInvoke(delegate()
{
  PropertyChanged(this, new PropertyChangedEventArgs("FileLength"));
});

Me.Dispatcher.BeginInvoke(Function() Do
    RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs("FileLength"))
End Function)

<br />
files.Count(f => f.Status == FileUploadStatus.Uploading || f.Status == FileUploadStatus.Resizing)<br />

<br />
files.Count(Function(f) f.Status = FileUploadStatus.Uploading OrElse f.Status = FileUploadStatus.Resizing)<br />

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data;
using System.ComponentModel.DataAnnotations;

namespace MvcApplication1.Models
{
    public class GuestResponse
    {
        public string _email;

        [Required(ErrorMessage = "Please enter your email address")]
        [RegularExpression(".+\\@.+\\..+",
        ErrorMessage = "Please enter a valid email address")]
        public string Email
        {
            set { _email = value; }
            get { return _email; }
        }

         public GuestResponse()
        {
        }
        
        public GuestResponse(string email)
        {
            this._email = email;
        }       
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data;
using System.ComponentModel.DataAnnotations;

namespace MvcApplication1.Models
{
    public class GuestResponse
    {
        public string _name;

        public string Name
        {
            set 
            { 
               
                if (value == null)
                {
                    throw new ArgumentException(string.Format("Enter a value."));
                } else
                     _name = value;
            }

            get { return _name; }
        }

        public GuestResponse()
        {
        }
        
        public GuestResponse(string name, string email, string phone, Boolean attend)
        {
            this._name = name;

        }
   
    }
}