After installing the extension here is how to use it:
- Have a new or existing solution with two different projects where you want to share code, such as a solution that contains an iOS project and an Android project.
- Add a new project for code sharing, use the "Shared Project (Empty)" template:
Note: even if you don't have a Windows 8.1 project in your solution, adding a universal shared project will require you to get a Windows 8.1 developer license, at least it did for me.
- In the universal project add any shared modules, classes, constants, etc that you want.
- In each of the platform specific projects under references right click and select the new "Add Shared Project Reference"
- A list of all shared projects in the solution will be displayed, select the one you want:
That's all there is to it. You can directly create empty shared universal projects and then through the Visual Studio UI add references to them to platform specific projects. No direct editing of the projects required. It would be nice if adding the Universal shared project didn't require a Windows 8.1 developer license if you don't have a Windows 8.1 platform specific project in your solution, but that's a minor nit.