Where is MVC3's App_Code folder

This post contains a nicely succinct explanation for implementing razor helpers. But it refers to the use of the 'App_Code' folder - something i can't get my MVC3-transitioned-from-MVC2 project to create. I understand this has to do with WebSite vs. Web App but to be honest - i can't remember if the original creation was site or app. Since there's menu selection 'Convert to Web Application' seems it was created as a Web Site. But then there should be a App_Code dir, yes?

Attempting to recreate the steps from the original post (within a manually created 'App_Code' folder) presents pre-compile errors (MyHelpers does not exist in this context) - but the strategy _does work. - at least the simple hello stuff did. so i shouldn't argue with success? MVC3/开发者_如何学编程Razor isn't fully intellisensed yet?

thx

I created an app_code directory by just creating a folder called app_code. MVC3 dealt with this file correctly by creating static methods for the code I put in there. When I reopened my solution later, the app_code file had disappeared. I eventually found that the app_code file was marked as a hidden folder by visual studio. In this virtual machine I have the RTM VS 2010. not sure if this was fixed in SP1.