Ajax.ActionLink(),增加对img的支持

@Ajax.ActionLink("ActionLink", "Index", "Home", "https", "www", "title", new { id = 1, type = 1 }, new AjaxOptions { HttpMethod = "Post", UpdateTargetId = "detailsID", InsertionMode = InsertionMode.Replace }, new{ id = "testid"})

public static IHtmlString ImageActionLink(this AjaxHelper helper, string imageUrl, string altText, string actionName, object routeValues, AjaxOptions ajaxOptions, object htmlAttributes = null)
        {
            var builder = new TagBuilder("img");
            builder.MergeAttribute("src", imageUrl);
            builder.MergeAttribute("alt", altText);
            builder.MergeAttributes(new RouteValueDictionary(htmlAttributes));
            var link = helper.ActionLink("[replaceme]", actionName, routeValues, ajaxOptions).ToHtmlString();
            return MvcHtmlString.Create(link.Replace("[replaceme]", builder.ToString(TagRenderMode.SelfClosing)));
        }

@Ajax.ImageActionLink(Url.Content("~/Content/Images/favorite.gif"),"收藏", "AddFavorite",null, new AjaxOptions { UpdateTargetId = "addfavorite" })