点击 此处 了解更多信息，但基本上不需要扩展方法.它已经内置了，只是不是以非常直观的方式.

Click here for more information, but esentially there is no need for extension methods. It's already baked in, just not in a very intuitive way.

Url.Action("Action", null, null, Request.Url.Scheme);