ASP.NET MVC 2 Html.ImageActionLink Helper using Microsoft.Web.Mvc

ContentHelper.cs

// After using the Microsoft.Web.Mvc Html.ActionLink<TController>(...  Expression<Action<TController>> action ...);
// I was unable to use that for a Image, so here's the code for it:
// **** :) no more magic strings for image linking to actions.
// usage: 
//  <%= Html.ImageActionLink<HomeController>(
//                           x => x.ChangeCulture(Culture.pt, this.Request.RawUrl), 
//                           Culture.pt.ToString() + ".png")
//  %>


 public static class ContentHelper
    {
        public static readonly string CssPath = "~/Content/css/";
        public static readonly string JsPath = "~/Content/javascript/";
        public static readonly string ImgPath = "~/Content/images/";

        public static string Css(this UrlHelper helper, string file)
        {
            return helper.Content(String.Format(CssPath + "{0}", file));
        }

        public static string Js(this UrlHelper helper, string file)
        {
            return helper.Content(String.Format(JsPath + "{0}", file));
        }

        public static string Img(this UrlHelper helper, string file)
        {
            return helper.Content(String.Format(ImgPath + "{0}", file));
        }

        public static MvcHtmlString ImageActionLink<TController>(this HtmlHelper helper, Expression<Action<TController>> action, string imageSource) where TController : Controller
        {
            return ImageActionLink<TController>(helper, action, imageSource, (object) null);
        }

        public static MvcHtmlString ImageActionLink<TController>(this HtmlHelper helper, Expression<Action<TController>> action, string imageSource, object htmlAttributes ) where TController : Controller
        {
            
            var valuesFromExpression = Microsoft.Web.Mvc.Internal.ExpressionHelper.GetRouteValuesFromExpression<TController>(action);
            var urlHelper = new UrlHelper(helper.ViewContext.RequestContext, helper.RouteCollection);
            var aBuilder = new TagBuilder("a");
            aBuilder.MergeAttribute("href", urlHelper.Action((string)valuesFromExpression["Action"], (string)valuesFromExpression["Controller"], valuesFromExpression));

            var imgBuilder = new TagBuilder("img");
            imgBuilder.MergeAttributes(new RouteValueDictionary(htmlAttributes));
            imgBuilder.MergeAttribute("src", Img(urlHelper, imageSource));

            aBuilder.InnerHtml = imgBuilder.ToString(TagRenderMode.SelfClosing);

            return MvcHtmlString.Create(aBuilder.ToString(TagRenderMode.Normal));
        }