創建兩個路線選擇到同一個頁面（MVC）

Question

我希望能夠訪問同一頁面兩種不同的方式：

首先，用一個參數，顯示一些特定的信息。

 routes.MapRoute(
      "About", 
      "About/{id}", 
      new { controller = "About", action = "Index" } 
     ); 

二，沒有參數，顯示一般的東西。

 routes.MapRoute(
      "About", 
      "About", 
      new { controller = "About", action = "Index" } 
     ); 

我該如何構建接受這兩個選項的路線？

Answer 1

routes.MapRoute(
    "About", 
    "About/{id}", 
    new { controller = "About", action = "Index", id = UrlParameter.Optional } 
); 

然後：

public ActionResult Index(string id) 
{ 
    // if id = null => /About was requested 
    // if id != null => /About/abc was requested 
    ... 
}