How to add subdomain for Area in mvc?

I have a web application using asp.net MVC and have multiple Areas:

• localhost
• localhost/admin/home/index
• localhost/tech/home/index

How can I add a subdomain for this Areas? example:

• localhost
• admin.localhost/home/index
• admin.tech/home/index

Resolve:

1.   Create class SubDomainRoute.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Web.Routing;

namespace Web.App_Start
{
    public class SubDomainRoute : Route
    {
        private readonly string[] namespaces;

        public SubDomainRoute(string url, object defaults, string[] namespaces)
            : base(url, new RouteValueDictionary(defaults), new MvcRouteHandler())
        {
            this.namespaces = namespaces;
        }

        public override RouteData GetRouteData(HttpContextBase httpContext)
        {
            var url = httpContext.Request.Headers["HOST"];
            var index = url.IndexOf(".");

            if (index < 0)
                return null;

            var subDomain = url.Substring(0, index);
            if (subDomain == "admin")
            {
                var routeData = base.GetRouteData(httpContext);

                if (this.namespaces != null && this.namespaces.Length > 0)
                {
                    routeData.DataTokens["Namespaces"] = this.namespaces;
                }
                routeData.DataTokens["Area"] = "Admin";
                routeData.DataTokens["UseNamespaceFallback"] = bool.FalseString;

                return routeData;
            }

            return null;
        }

        public override VirtualPathData GetVirtualPath(RequestContext requestContext, RouteValueDictionary values)
        {
           
            //if (true)
            //{
            //    return base.GetVirtualPath(requestContext, values);
            //}

            return null;
        }
    }
}

2. Change Route Default in Area:
public override void RegisterArea(AreaRegistrationContext context)
        {
            context.Routes.Add("Admin_Default", new SubDomainRoute(
                "{controller}/{action}/{id}",
                new { area = "Admin", controller = "Home", action = "Index", id = UrlParameter.Optional },
                new[] { typeof(Controllers.HomeController).Namespace } // Namespaces defaults
            ));
        }

3. Reference domain and subdomain to webapplication