[HttpPost]
 public ActionResult UploadFiles(HttpPostedFileBase[] image1, int id)
 {
       var isAjax = this.Request.IsAjaxRequest();
       Thread.Sleep(3000);
       return Json(new { FileName = "/Uploads/filename.ext" }, "text/html",   JsonRequestBehavior.AllowGet);
 }

namespace Project.Models
{
    public class EmployeeCreateModel
    {
        [Required]
        [Display(Name = "آدرس ایمیل")]
        [EmailAddress(ErrorMessage = "لطفاً {0} معتبر وارد کنید.")]
        [Remote("UserExistByEmailValidation",
            HttpMethod = "POST",
            ErrorMessage = "ایمیل وارد شده هم اکنون توسط یکی از کاربران مورد استفاده است.‏")]
        public string Email { get; set; }
    
     ...

     }
}

namespace Project.Web.Controllers
{
    [RoutePrefix("UserValidation")]
    [Route("{Action}")]
    [OutputCache(Location = OutputCacheLocation.None, NoStore = true)]
    public partial class UserValidationController : Controller
    {
        readonly IUserService<User> _userService;
        readonly IUnitOfWork _uow;

        public UserValidationController(IUnitOfWork uow, IUserService<User> userService)
        {
            _userService = userService;
            _uow = uow;
        }

        [HttpPost]
        [Route("~/CheckEmail", Name = "UserExistByEmailValidation")]
        public virtual JsonResult CheckEmail(string email)
        {
            return Json(!_userService.UserExistsByEmail(email));
        }

        [HttpPost]
        [Route("~/CheckEmailForOtherUser", Name = "EmailExistForOtherUserValidation")]
        public virtual JsonResult CheckEmailForOtherUser(string email, int id)
        {
            return Json(!_userService.EmailExistForOtherUser(email, id));
        }
    }
}

@section Scripts {
    @Scripts.Render("~/bundles/jqueryval")
}

    public class EfTagService : ITagService
    {
        IUnitOfWork _uow;
        readonly IDbSet<Tag> _tags;

        public EfTagService(IUnitOfWork uow)
        {
            _uow = uow;
            _tags = _uow.Set<Tag>();
        }

        public bool CreateTag(Tag tag)
        {
            // ...
        }

        public List<Tag> GetTagsByName(string[] tagNames)
        {
            // return ...
        }

    }

public class EfPostService : IPostService
{
        IUnitOfWork _uow;
        readonly IDbSet<Post> _posts;
      
         //این قسمت
        private EfTagService _tagService;


        public EfPostService(IUnitOfWork uow)
        {
            _uow = uow;
            _posts = uow.Set<Post>();

             //این قسمت
            _tagService = new EfTagService(_uow);
        }

        public void AddTagsToPost(Post post, string[] tagsList)
        {
            if (post.Tags != null && post.Tags.Any())
                post.Tags.Clear();

             //این قسمت
            var listOfActualTags = _tagService.GetTagsByName(tagsList);
            var listOfActualTagNames = listOfActualTags.Select(x => x.Name.ToLower()).ToList();

            foreach (var tag in tagsList)
            {
                if (!listOfActualTagNames.Contains(tag.ToLowerInvariant().Trim()))
                {
                    Tag newTag = new Tag() { Name = tag };
                 
                      //این قسمت
                    _tagService.CreateTag(newTag);

                    post.Tags.Add(newTag);
                }
            }
            // ...
         
        }
}