.NET 3.5 application running a .NET 4.0 API [closed]

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in it开发者_JS百科s current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 11 years ago.

We have a few applications that are under the .net 3.5 framework. We have a code API (library for reusable access to central database information) that is distributed. We have moved that piece of the site to that .net 4.0 framework.

My question is; how can we make the api available to the applications that are not in a position to migrate to the .net 4.0 framework yet? The new functionality that needed by everyone is under the 4.0 framework.

Should I just create two APIs?

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To the comments left on the question; if you don't have anything constructive, please don't post.

I'm not sure what the confusion about a custom API is not clear.

We are very familier with writing applications, and are in the process of migrating to the 4.0 framework. It can be costly for a company (and it's clients) to have to re-write/update an application every time a new framework comes out.

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I am afraid you'll have to recompile the older applications with the .NET 4 framework for them to work with your new API.

Or you can re-compile your API (If possible) targeting the 3.5 framework.

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Just recompile in .NET 4 - best solution.

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As long as you haven't explicitly targeted the 3.5 framework in your configuration files, and you haven't used any features which broke in .NET 4.0, you should be good to go as is.