Target .net 4.5, but deployment in .net 4.0 is possible?

Question

I need to work in accordance with the following policy: “all software must be version 1 behind”, I don’t particularly like it, and I can’t change it. so that would mean that our production machine would only work until .NET 4.0, only when .NET 5 is released, we can upgrade to 4.5! stupid, I know.

so I’m currently planning to propose that the dev machines upgrade to Visual Studio 2012 and target .NET 4.0, which is now fine,

We have several projects in the near future that will require a lot of asynchronous programming, and I want to be able to use all the syntactic advantages of 4.5, asynchronous / pending and all other improvements.

so what are the options! accept "it's just life" and only target 4.0 and moan! or is there a way to configure 4.5 in dev and import about 4.5 DLLs into prod, is this possible? ultimately, can you design to take advantage of 4.5 features anyway and deploy to 4.0? any advice please ...

Answer 1

You are looking for Microsoft.Bcl.Async .

Answer 2

Note that it is not supported to create a .NET4.5 application, and then tries to reassign it to .NET4.0. Basically, when creating an application with .NET4.5, you can use the new APIs added in 4.5 and missing in 4.0. Thus, your application will not work properly.