MVC LocalizationHelper.cs

    public static class LocalizationHelpers
    {
        public static string Resource(this HtmlHelper htmlhelper, string expression, params object[] args)
        {
            string virtualPath = GetVirtualPath(htmlhelper);

            return GetResourceString(htmlhelper.ViewContext.HttpContext, expression, virtualPath, args);
        }

        public static string Resource(this Controller controller, string expression, params object[] args)
        {
            return GetResourceString(controller.HttpContext, expression, "~/", args);
        }

        private static string GetResourceString(HttpContextBase httpContext, string expression, string virtualPath, object[] args)
        {
            var context = new ExpressionBuilderContext(virtualPath);
            var builder = new ResourceExpressionBuilder();
            var fields = (ResourceExpressionFields)builder.ParseExpression(expression, typeof(string), context);

            if (!string.IsNullOrEmpty(fields.ClassKey))
                return string.Format((string)httpContext.GetGlobalResourceObject(fields.ClassKey, fields.ResourceKey, CultureInfo.CurrentUICulture), args);

            return string.Format((string)httpContext.GetLocalResourceObject(virtualPath, fields.ResourceKey, CultureInfo.CurrentUICulture), args);
        }

        private static string GetVirtualPath(HtmlHelper htmlHelper)
        {
            string virtualPath = null;
            var view = htmlHelper.ViewContext.View as WebFormView;

            if (view != null)
            {
                virtualPath = view.ViewPath;
            }
            return virtualPath;
        }
    }