Conditional compilation does not work - visual-studio-2010

Question

Reading this post here on stackoverflow want to load a different css when compiling for release mode.
Code:
#{ #if (Debug)
<link href="#Url.Content("~/Content/Site.css")" rel="stylesheet" type="text/css" />
#else
<link href="#Url.Content("~/Content/Site-min.css")" rel="stylesheet" type="text/css" />
#endif
}
Attempt 2
#{ #if (Debug) }
<link href="#Url.Content("~/Content/Site.css")" rel="stylesheet" type="text/css" />
#{ #else }
<link href="#Url.Content("~/Content/Site-min.css")" rel="stylesheet" type="text/css" />
#{ #endif }
I tried to DEBUG in uppercase
But no change has no effect when compiling Debug to Release

Answer 1

According to this SO post, if you want this sort of thing to work, you can use a property in your Model to drive the View's conditional stuff, so the C# sets the Model's boolean (IsDebug, or whatever) via the compile time directive stuff and the View relies on that.
So your Model would end doing something like:
bool IsDebug = true;
#if (!DEBUG)
IsDebug = false;
#endif
and your View would do something like:
#if(Model.IsDebug)
{
}
else
{
}
You could also use ViewBag/ViewData to hold that boolean value too, I suppose.
UPDATE:
Base on your comments, here's something you could do:
Create a new BaseController class which inherits from Controller.
public abstract class BaseController : Controller
{
...
protected BaseController()
{
bool indebug = false;
#if DEBUG
indebug = true;
#endif
ViewBag.InDebug = indebug;
}
}
and have your Controllers inherit from this rather than Controller.
Then in your _Layout.cshtml you could do this:
#if (ViewBag.InDebug)
{
}
else
{
}
This seems to work OK.