Use older dlls (.NET) in Windows Store app?

Question

I started work on porting an application I've written for deployment in the Windows 8 app store. This requires that the application be written against the subset of the .NET framework. My application follows an architecture where the core functionality is in it's own dll, and things like file system access are done through IoC. Basically, this means that the only dependency for the core dll is System. Because of this, I thought that porting would be a breeze - setup my IoC values and wire up a GUI then I'll be good to go. Only, I can't even reference my core dll from the windows store app (a.k.a. metro app).

Have I missed something? Do actually have to rewrite my core dll just for inclusion in the windows 8 app store? We're told that if you use a good architecture, then porting will be a breeze, and that's what I've done. Has that just been a big lie?

Answer 1

Windows store apps(formerly called metro style app) are limited to using the .NET Core Profile. I put some details about the Core Profile in my answer to this question. See Converting your existing .NET Framework code in this article more details. It's not your architecture, it's the subset of the .NET Framework that is available to a Windows store app. You may have to supplement some of the types you use in .NET with WinRT types instead.

Answer 2

I don't have an extensive knowledge and will try to stict to facts as I understand them. The Metro framework adds functionality, and limits functionality. There are heavy security restrictions and vast segments of the full .Net framework that are not available (for instance, you cannot use System.Data, some of the System.IO and file access methods have drastically changed). A Metro app is isolated, you're not going to be able to recurse all the files on the hard drive like you could in a standard application (my opinion that is, on top of security by isolation it's an encouragement to push you into the cloud for storage needs).

Unless things have changed, PInvoke is limited to "approved" Win32 API methods.

See this link for some alternatives to common Win32 API needs: http://msdn.microsoft.com/en-us/library/windows/apps/hh464945.aspx

See this link for approved Win32/COM API's: http://msdn.microsoft.com/en-us/library/windows/apps/br205762.aspx

It's hard to say whether a "good" architecture will be a breeze to port without knowing what's in the code in that architecture. In my utility framework I've had things that ported very easily (or at least were straightforward) and things that were a complete wash that required a lot of rewriting (The loss of System.Data for instance is a sore spot for me). There are things that can be designed well but when you take out the underlaying code in the framework or API it was written with it will require rewriting.

Answer 3

I had the same problem: a project for Metro app don't load dll create with framework .4. I changed the framework from 4 to 3.5 for the dll and now the Metro project see them.