DomainService Class

Domain services are Windows Communication Foundation (WCF) services that encapsulate the business logic of an application. A domain service exposes a set of related operations in the form of a service layer. When you create an instance of a domain service, you specify the data operations that are permitted through the domain service.

The DomainService class is the base class for all classes that serve as domain services. The LinqToEntitiesDomainService<TContext> class derives from the DomainService class and is used when interacting with LINQ to Entities models.

A domain service class must be marked with the EnableClientAccessAttribute attribute to make the service available to the client project. The EnableClientAccessAttribute attribute is automatically applied to a domain service when you select the Enable client access check box in the Add New Domain Service Class dialog box.

For more information, see Domain Services.

The following example shows a domain service that exposes an operation for registering a new user. The GetUsers method must be included to ensure that the NewUser entity class is generated for the client project.

namespace ExampleNavigationApplication.Web
{
    using System;
    using System.Collections.Generic;
    using System.ServiceModel.DomainServices.Hosting;
    using System.ServiceModel.DomainServices.Server;
    using System.Web.Security;
    using System.Web.Profile;


    [EnableClientAccess()]
    public class RegistrationDomainService : DomainService
    {
        public void AddUser(NewUser user)
        {
            MembershipCreateStatus createStatus;
            Membership.CreateUser(user.UserName, user.Password, user.Email, user.SecurityQuestion, user.SecurityAnswer, true, null, out createStatus);

            if (createStatus != MembershipCreateStatus.Success)
            {
                throw new DomainException(createStatus.ToString());
            }

            ProfileBase profile = ProfileBase.Create(user.UserName, true);
            profile.SetPropertyValue("DefaultRows", user.RecordsToShow);
            profile.Save();
        }

        public IEnumerable<NewUser> GetUsers()
        {
            throw new NotSupportedException();
        }
    }  
}

Reference