How to create custom viewengine in MVC 2

As is we know, by default, the viewengine of MVC is webformsviewengine. After refector the source code, I find that the engine implementIviewAndVirtualpathproviderviewengine. So we also can create custom engine.

using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.Mvc;using System.Xml;using System.Xml.Xsl;using System.Xml.Linq;namespace MvcApplication1.Models{    public class XSLTViewEngine:VirtualPathProviderViewEngine    {        public XSLTViewEngine() {            ViewLocationFormats = PartialViewLocationFormats = new[] {                "~/Views/{1}/{0}.xslt","~/Views/Shared/{0}.xslt"            };        }        protected override IView CreatePartialView(ControllerContext controllerContext, string partialPath)        {            return new XSLTView(controllerContext, partialPath);        }        protected override IView CreateView(ControllerContext controllerContext, string viewPath, string masterPath)        {            return new XSLTView(controllerContext, viewPath);        }    }    public class XSLTView : IView    {        private readonly XslCompiledTransform _template;        public XSLTView(ControllerContext context, string viewPath)        {            _template = new XslCompiledTransform();            _template.Load(context.HttpContext.Server.MapPath(viewPath));        }        #region IView Members        public void Render(ViewContext viewContext, System.IO.TextWriter writer)        {            XDocument xmlModel = viewContext.ViewData.Model as XDocument;            if (xmlModel != null)            {                _template.Transform(xmlModel.CreateReader(), null, writer);            }            else throw new ArgumentException("Invalid xdocument");        }        #endregion    }}

After that, we shoshould register the viewengine in global. asax.

 protected void Application_Start()        {            AreaRegistration.RegisterAllAreas();            RegisterRoutes(RouteTable.Routes);            ViewEngines.Engines.Clear();            ViewEngines.Engines.Add(new XSLTViewEngine());        }

Of course, we can sepecify The Engin in controller.

        public ActionResult Index()        {            ViewResult result =  View(GetBooks());            result.ViewEngineCollection = new ViewEngineCollection(){               new XSLTViewEngine()             };            return result;        }