Multiplatform MSBuild project file

I'm currently working on a project which source code should be as portable as possible; that is, the project (in C#, but it is not very relevant) represent an application that should be executed on Android (with Mono-Android), on iPhone (with MonoTouch) and WinMobile (with official Compact Framework). Without going into details, the corresponding MSBuild solution consists of an independent-platform library (from a source code point of view, at least) which declare various interfaces and classes that represent an abstraction of each feature that is not common to the various platform (开发者_Python百科i.e. the UI). In addition, there are a corresponding library that specialize (for each platform) the "base library"; the effective application executable is a program that uses the abstraction and the common standard libraries.

Developing on WinMobile and Android is not really a problem: Mono-Android add-in can be installed on VS 2010, so both platforms can be handled with MS VS.

Initially the solution was created in VS, so the initial configuration and the related projects (Android and WinMobile) are automatically generated.

After that I've imported the solution in MonoDevelop under Mac (the only platform that is officially supported by MonoTouch), and I've created the project for the iPhone library; switching the configuration to generate the assemblies (iPhoneSimulator) the "base library" was not possible to compile due to a missing project type configuration; specifically, the GUID used by MonoTouch for <ProjectTypeGuids> is {E613F3A2-FE9C-494F-B74E-F63BCB86FEA6}; adding this GUID I can now compile "base library" in MonoDevelop.

The problem arises when I try to re-import the solution in VS: since there's no Windows version of MonoTouch, VS cannot find the add-in for the specified project type, and the project doesn't load.

Looking to the specifications of MSBuild project file, it seems that there are tons of options that cannot be set or modified within the project/solution editor in VS; however the format is quite complicated and now I'm asking your help!

Is there a way to specify in the project file that a project type is present only if a particular configuration is selected independently to which is the environment I'm using?

The general approach is something like this; a condition that progressivly builds your property, referencing any value the property already may have:

<ProjectTypeGuids
   Condition="'$(BuildingInsideVisualStudio)' != 'true'"
   >;{E613F3A2-FE9C-494F-B74E-F63BCB86FEA6}"</ProjectTypeGuids>
<ProjectTypeGuids>{OTHER-GUIDS-HERE}$(ProjectTypeGuids)</ProjectTypeGuids>

This will detect the VS condition (when building) and omit the unkonwn guid. I'm not sure however if it will work when the project is opened, this property might only apply to building. There may be a similar "sentinal" property for building on Mono, and you can reverse the condition.

I solved an unrelated, but very similar issue of cross-platform development by excluding the files that presented themselves as cranky when going between Linux and Windows. I have my project under source control and utilized that to keep things working cooperatively. http://www.aydabtudev.com/2011/05/what-goes-into-source-control-android.html

It's not a 1-to-1 for your issue, but it might give you clues/ideas on how to solve your problem.