Asp.net mvc 3 具有可选第一个参数的MVC3路由

我的站点当前设置了以下路径：

        routes.MapRoute(
            "BrandList",
            "Brands",
            new { controller = "Brand", action = "Index" }
        );

        routes.MapRoute(
            "BrandProducts",
            "{brand}/Products",
            new { controller = "Brand", action = "Products", manufacturer = "" },
            new { manufacturer = new BrandConstraint() }
        ); 
        routes.MapRoute(
            "Product",
            "{brand}/{partNumber}",
            new { controller = "Product", action = "Details", brand = "" },
            new { manufacturer = new BrandConstraint() }
        );

这会产生如下URL

http://oursite/Brands                     -> List of all brands
http://oursite/SomeBrand                  -> List of one brand's products
http://oursite/SomeBrand/ProductA         -> Details for product

不过，我刚收到指令，我们现在需要在上面提供相同的页面

http://oursite/Brands                     -> List of all brands
http://oursite/SomeBrand                  -> List of one brand's products
http://oursite/Brands/SomeBrand           -> List of one brand's products
http://oursite/SomeBrand/ProductA         -> Details for product
http://oursite/Brands/SomeBrand/ProductA  -> Details for product

我知道我可以再创建两条路线，与当前的

BrandProducts

和

Product

路线相同，在开始时添加额外的“Brands/”。如果需要，我会这样做，但我真的更希望不必复制每个路线入口（不止这两个）

---

有人有什么建议吗

您可能只想尝试使用Url重写，而不是增加指向同一位置的其他路由的复杂性

此外，拥有多个有效的URL规范格式也不好，一个URL应该真正指向“正确”的URL